productivity,water-andnitrogen-useefficiency,and...

Research ArticleProductivity Water- and Nitrogen-Use Efficiency andProfitability of Pearl Millet (Pennisetum glaucum) underDifferent Nitrogen Applications in Semiarid Region of Nigeria

Hakeem A Ajeigbe 1 Folorunso M Akinseye12 Alpha Y Kamara3 AbdulAzeez Tukur1

and Abubakar Hassan Inuwa1

1International Crop Research Institute for the Semi-Arid Tropics (ICRISAT) Kano Nigeria2Department of Meteorology and Climate Science Federal University of Technology Akure Nigeria3International Institute of Tropical Agriculture (IITA) Kano Nigeria

Correspondence should be addressed to Hakeem A Ajeigbe hajeigbecgiarorg

Received 3 February 2020 Revised 15 July 2020 Accepted 6 August 2020 Published 27 August 2020

Academic Editor Mathias N Andersen

Copyright copy 2020 Hakeem A Ajeigbe et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

An experiment was conducted to examine the performance of pearl millet under different nitrogen (N) fertilizer rates in twolocations in the semiarid zone of Nigeria e objective was to evaluate the effects of different N rates on pearl millet yields water-and nitrogen-use efficiency and profitability Grain yield increased by 23 26 32 32 and 27 and by 38 41 54 58 and 56compared to unfertilized plots when applying 20 40 60 80 and 100 kg Nhaminus1 in Minjibir and Gambawa respectively Similarlystalk yield increased by 4 3 9 9 and 9 and by 16 24 36 40 and 37 compared to unfertilized plot when applying 20 40 60 80and 100 kg Nhaminus1 in Minjibir and Gambawa respectively e variations in GY that could be explained by TWU and NUE were28 and 26 in Minjibir and 46 and 41 respectively in Gambawa ere was a strong and positive correlation (R 081 andR 095) between WUE and GY across N-fertilizer rates and pearl millet varieties in both locations An increase in N-fertilizerlevels increased WUE confirming the optimal application of 60 kg Nhaminus1 in Minjibir and of 80 kg Nhaminus1 in Gambawa Similarlythe highest net economic return (NER) of US$610 haminus1 was obtained at 60 kg Nhaminus1 in Minjibir and the highest NER ofUS$223 haminus1 was obtained at an application rate of 80 kg Nhaminus1 in Gambawa Break-even yield was above 1000 kg haminus1 signifyingthat average farmer with a mean yield of less than 1000 kg haminus1 produces millet at a loss

1 Introduction

Pearl millet (Pennisetum glaucum (L) R Br) is drought-tolerant and early maturing with high water-use efficiencybut productivity may be greatly influenced using appropriatenitrogen (N) inputs for maximum profitability [1] Pearlmillet provides grain for human consumption and stover forlivestock in the arid and semiarid tropics [1 2] It has highnutritional value and exceptional tolerance to drought andhigh temperature [3 4] Under semiarid conditions rainfalland soil fertility dictate crop performance and croppingpatterns [5 6] Pearl millet flourishes satisfactorily and canbe cultivated under low rainfall (200ndash250mm) which makes

it one of the most reliable cereal crops in the arid andsemiarid tropics [7 8]e annual pearl millet production inNigeria between 2014 and 2016 ranged from 115 to 155million tons representing about 5 of total world pro-duction with the average yield of 903 kg haminus1 which rankedNigeria as the third worldrsquos largest producer after Niger andIndia [1] In Nigeria pearl millet is grown primarily for grainused for human consumption e stover is also of greateconomic importance for livestock feed building materialsand fuel Although average pearl millet yields worldwide arelower than the average yields of other cereal crops [4]improved agronomic practices and varieties have beenfound to lead to more efficient use of photosynthetically

HindawiInternational Journal of AgronomyVolume 2020 Article ID 1802460 12 pageshttpsdoiorg10115520201802460

active radiation (PAR) water and nutrients especially Nresulting in a significant increase in grain and stover yields[9]

Despite the fact that the crop can be grown in low rainfallbelt studies have shown that millet production in WestAfrica is primarily constrained by limited water supply thatdetermines the amount of water used for growth andproductivity [10 11] Rainfall and soils are the major en-vironmental resources that merit detailed analysis in theefforts to increase millet production [11] e inadequatesupply of plant nutrients by most farmers restricts the ef-ficient use of limited rainfall and this results in unstable lowproductivity of millet [5] Similarly studies have shown thatgreater water-use efficiency could be achieved through ef-ficient use of fertilizers [11 12] without underestimating therole of plant genetics [13] Additionally demand for food bythe growing population in Nigeria will require that we in-crease resource-use efficiency of water and nutrient forcereal crops including pearl millet Among the nutrients Nis the most limiting nutrient for cereal production on de-graded semiarid soils although P is also a major problem [5]Monitoring plant N to ensure an adequate supply for plantrequirements is necessary to have optimum growth im-proved NUE and to reduce N losses [14] In rainfedcropping systems adapting N management to water con-straints may help to mitigate N losses and therefore increaseNUE In its simplest definition NUE is the grain yield perunit of supplied N [15] It is affected by several factors andprocesses including N uptake translocation assimilationand remobilization [16] NUE is an important target for cropimprovement [17] though crop-specific managementstrategies may be required Improvement of NUE is a way toefficiently use inorganic fertilizer which is an essentialprerequisite for the expansion of crop production intomarginal lands with low nutrient availability [18] e un-derstanding of NUE in pearl millet across the growing areasis very important for economic environmental and pro-ductivity reasons [19] is is due to unbalanced applicationand high cost of fertilizer or fertilizer availability whichconstitute a big constrain to resource-poor farmers inNigeria [20] In addition with the advocacy of improvedproduction practices and cultivars the use of nitrogenfertilizers is increasing quantitatively but responsive yieldsto N are substantially fading over the years in all crops [19]including pearl millet [21]us balancing the N rate WUEand yield is an important problem in dryland farmingsystems Classical reviews of fertilizers and efficient use ofwater for maize [6] concluded that in most cases when thewater supply is fixed any management factor that increasesyield would increase water-use efficiency It was reported in[11] that under Sahelian conditions 84 increase ofWUE inmillet (grain yield per mm rain) is due to the application ofmineral fertilizers e application of N increases WUE by15 and grain yield by 400 kg over control for sorghum cropcultivated under rainfed condition [22] Although im-provements in yield may be brought about by judiciousapplications of fertilizer a better understanding of inter-actions among precipitation fertilization and crop pro-duction is essential for efficient utilization of water resources

and N-fertilizers [23] A good plant N nutritional statusenhances millet tolerance to drought and enhances mor-phological traits thereby increasing yields [24] With av-erage or above rainfall N application and high plant densityincreased millet grain yield four- to fivefold Nitrogen ap-plication increased stover production by 33 in a dry yearand by 100 in a wetter year [25] N supply of sim30 kg Nha intwo split applications achieved good yields in average andwet years with only a small yield reduction in the droughtyear [25] A moderate increase of N supply for sorghum wasreported to improve water-use efficiency (WUE) undersemiarid environments [12] To attain high stable yields ofpearl millet by smallholder farmers that will deliver higherprofitability in the region would therefore require combi-nations of improved varieties optimum amounts of fertil-izer and good cultural management practices for efficientutilization of limited water ere is limited information onthe response of new improved diverse millet varieties toapplied N in terms of grain yield (GY) total water use(TWU) nitrogen-use efficiency (NUE) and water-use effi-ciency (WUE) e objectives of the trial were to assess thedirect effect of nitrogen application and varieties on pro-ductivity and water- and nitrogen-use efficiency of pearlmillet and to identify optimal N-fertilizer rate for higherprofitability of pearl millet production relative to the studyareas

2 Materials and Methods

21 Description of the Experimental Sites e experimentswere conducted during the 2014 and 2015 growing seasons attwo sites within the semiarid region of Nigeria e firstlocation was ICRISAT research field situated within theInstitute for Agricultural Research (IAR) station Wasaivillage Minjibir Local Government Area of Kano State(latitude 1217degN and longitude 865degE 455m ASL) while thesecond location was within farmersrsquo field in GambawaGumel Local Government Area of Jigawa State (latitude12625degN and longitude 9325degE 370m ASL) Both sites arelocated in the Sudan Savanna agroecological zone wheresoils are mainly sandy and loamy of low fertility [26] etrials were conducted in different parts of the research farm(Minjibir) and farmers field (Gambawa) in the 2 yearsUndisturbed soil samples were randomly taken at a depth(0ndash20 cm) prior to sowing for each location in both growingseasons Soil samples were analysed at the Soil ScienceDepartment Laboratory Bayero University Kano Nigeriaey were analysed for particle size distribution organiccarbon (OC) pH and other chemical properties as describedin [27]

22 Experimental Design e experiment was a split plotdesign with four replicationsemain plot had six nitrogen(N) fertilizer levels (0 20 40 60 80 and 100 kg haminus1) andthe subplots randomised within the main plots had threepearl millet varieties (Jirani Super SOSAT and local con-trol) e details of the varieties used (Jirani Super SOSATand local) have been described by Ajeigbe et al [1]e gross

2 International Journal of Agronomy

size of each subplot was 15m2 (5m long by 3m wide) isconsisted of four ridges 5m long spaced at 75 cm apartPlanting was done at 50 cm between plants giving a totalplant population of 26667 hills haminus1

221 Field Management Data Collection and Analysise land was harrowed and ridged at 75 cm apart and sownon 7th July in Minjibir and 10th July in Gambawa in 2014cropping season while in 2015 growing season the exper-iments were sown on 3rd July in Minjibir and 22nd July inGambawa respectively Sowing was done by placing 5ndash7seeds per hole at a depth of 3ndash5 cm and seeds were thinned totwo (2) plants per hill between 2 and 3 weeks after planting(WAP) e N-fertilizer (urea) was applied in two splits (atplanting and 4 weeks after planting (WAP)) while 30 kgP2O5 haminus1 and 30 kg K2O haminus1 were applied during plantingacross N-fertilizer levels as single super phosphate andmuriate of potash respectively Weeding was carried outmanually to keep the fields weed-free e two centre rows(75m2) in each subplot were taken as the net plot and datawere collected from these net plots In both locations leafchlorophyll contents were measured at 3 and 6WAP using aSPAD-502 portable chlorophyll meter (Minolta TokyoJapan) All chlorophyll meter readings were taken midwaybetween the stalk and the tip of the leaf Leaf area index(LAI) at 6 and 9 WAP was measured with Accupar LP-80portable canopy analyser Days to 50 flowering andphysiological maturity were recorded when 50 of theplants per plot have flowered and 80 of the plot attainedmaturity Plant height was recorded and taken as the meanof five randomly plantsplot at maturity and measured fromthe ground base of the plant to the tip of the panicle Atmaturity stalk from the net plots was cut at the base and laidon the ground to sun dry until a constant weight was ob-tained Panicles were separated from the stalk and sun-drieduntil a constant weight was obtained (this took about 2weeks) which was recorded as panicle weight per plot epanicles were then threshed and the weight of grains wasrecorded as grain weight per plot e dry stalks wereweighed and recorded ese were extrapolated as paniclegrain and stalk yield per ha (kg haminus1) respectively Athousand seeds were picked per plot using a seed counterand weighed using a sensitive scale and recorded as 1000-seed weight Harvest index (HI) was computed as the ratio ofgrain yield (GY) to the total aboveground drymatter (TDM)

222 Total Water Use and Water-Use Efficiency underDifferent N Applications e estimation of total water use(TWU) for each N-fertilizer level between sowing andphysiological maturity was calculated Firstly we appliedequation (2) to compute daily evapotranspiration (ETo)using the daily records of minimum temperature maximumtemperature and solar radiations observed from the auto-matic weather station near the field experimental plots(lt2 km radius) Other parameters are constant values basedon the agroecological zone of reference ereafter thecumulative reference evapotranspiration (ETo) was com-puted from sowing to physiological maturity multiplied by a

recommended crop coefficient (Kc) for pearl millet [28] asdescribed in equation (1) e PenmanndashMonteith equationwas used to calculate daily reference evapotranspiration(ETo) equation (2) e variables of this equation weredescribed in FAO Irrigation and Drainage Paper no 56 [29]e method is of quite good accuracy and is usually used forcalculations of evapotranspiration from farmlands

TWU KcETo (1)

ETo 0408Δ Rn minus G( 1113857 + c(900T + 273)u2 es minus ea( 1113857

Δ + c 1 + 034u2( 1113857 (2)

where ETo is the daily reference evapotranspiration (mmday-1) from sowing to physiological maturity Rn is the netradiation at the crop surface (MJ m-2 day-1)G is the soil heatflux density (MJ m-2 day-1) T is the air temperature at 2mheight (degC) u2 is the wind speed at 2m height (m s-1) es is thesaturation vapour pressure (kPa) ea is the actual vapourpressure (kPa) es minus ea is the saturation vapour pressuredeficit (kPa) D is the slope vapour pressure curve (kPadegC-1)and c is the psychrometric constant (kPadegC-1)

From the above daily ETo computed cumulative valuesfrom sowing to physiologically maturity at each N-fertilizerlevel were derived

Total water use (TWU) obtained from equation (1) wasused to calculate water-use efficiency (WUE) in equation(3) Water-use efficiency refers to the ratio of water used inplant metabolism to water lost by the plant throughtranspiration and soil evaporation (evapotranspiration)Water-use efficiency was calculated for only final grainyield at harvest maturity using the following equations[30]

WUE Y

TWU (3)

where Y is the grain yield (kghaminus1) and TWU is the totalwater use at a different level of N (mm)

23 Nitrogen-Use Efficiency (NUE) e nitrogen-use effi-ciency was calculated using the following formula [1631]and reported as kg grainkg N applied

NUE Yf minus Yc

Na

(4)

where Yf is the grain yield (kgha) in the fertilized plot Yc isthe grain yield (kgha) in control plot and Na is the nitrogen(N) applied (kgha)

231 Economic Analysis Partial budgeting analysis wasused to estimate the net income and benefit-cost ratio[32ndash34] for both sites e economic analyses were per-formed to compare the profitability of producing pearl milletvarieties under different N-fertilizer rates in both locationsbased on the current agronomic practices e average pearlmillet prices at the prevailing market price were surveyed atharvest in the study areas e millet grain and stalk valueper unit were determined based on the prevailing price in the

International Journal of Agronomy 3

different locations and extrapolated for value per ha basedon their respective yield per ha assuming there was no costborne for storage e total cost of production (TCP) is thecost of all recommended and variable inputs including la-bour that was used per treatment ese include expendituretowards land preparation seed and sowing fertilizers andtheir application harvesting threshing and bagging Totalrevenue (TR) is the total value of the grain and stalk har-vested from the plot Net economic returns (NERs) are thedifference between TR and TCP Benefit-cost ratio (B C) isthe ratio of NER by TCP (B CNERTCP) Break-evenyield was calculated by dividing the cost of production by theaverage market price of pearl millet at each location

232 Statistical Analyses All the data collected and com-puted were subjected to analysis of variance (ANOVA) usingGenStat analytical tool (19th edition) Year N-fertilizerlevels and variety are taken as factors to determine theireffect and interactions on different variables e treatmentmeans that were significantly different at 5 were comparedusing least significant difference (LSD) e relationshipbetween the characters evaluated was established at LSD(5) probability [35] In addition regression analysis wasused to establish the relationship of TWU and NUE on grainyield across the N rate as an expression of their contribution

3 Results

31 Soil Characteristic andWeather Indices Table 1 presentsthe results of the soil analysis of the experimental sites atprofile depth (0ndash20 cm) e soil texture is characterized assandy to sandy loam soil pH is slightly acidic (55 to 64)e soil organic carbon (OC) content was generally low andhigher values (196 g kgminus1 and 259 g kgminus1) were recorded ineach year in Minjibir compared to Gambawa (145 g kgminus1

and 201 g kgminus1) for 2014 and 2015 respectively e totalnitrogen content was 016 and 070 g kgminus1 at Minjibir and012 and 070 g kgminus1 at Gambawa while the availablephosphorus varied from 39 to 45mg kgminus1 in both seasons

e intensity and total rainfall were high indicating dailyrainfall ge40mm for many days in 2014 (827mm in 34 rainydays) compared to 2015 (598mm in 38 rainy days) atMinjibir (Figures 1(a) and 1(b)) In Gambawa (Figures 1(c)and 1(d)) the rainfall received in both seasons were closewith the total amount of rainfall 440mm with 34 rainy daysin 2014 compared to 2015 (500mm in 28 days) As shown inFigures 1(a)ndash1(d) daily evapotranspiration (ETo) showshigh variations Lowest values were recorded during thecropping seasons and thereafter the value increases e EToranged from 23 to 76mm in both seasons at Minjibir andvaried from 26 to 78mm at Gambawa

32 Leaf Chlorophyll Content (SPAD Readings) Leaf AreaIndex and Plant Height Table 2 shows the effect of N-fer-tilizer and pearl millet varieties on leaf chlorophyll (SPADreadings) content leaf area index (LAI) and plant height inboth locations and growing seasons (2014 and 2015) Signif-icant differences (Ple 005) were observed among the N

treatments for SPAD readings at 3 WAS SPAD readings weresignificantly higher at N rates of 80 and 100 kg Nhaminus1 than atother N levels in both locations Similar observations weremade at 6 WAS in Gambawa ere were no significant dif-ferences among N treatments for SPAD at 6 WAS in MinjibirIn both locations there were no significant differences in SPADreadings at 80 and 100 kg Nhaminus1ere were also no significantdifferences among the varieties SPAD reading at 3 and 6 WASexcept for SPAD at 6 WAS in Minjibir where the local varietyrecorded the highest mean SPAD value of 501

N-fertilizer level had no significant effect on LAI at 6WAS and 9 WAS in Minjibir N application howeversignificantly influenced LAI at 6 WAS in Gambawa At bothsites there were significant differences among varieties forLAI at 6 WAS At 9 WAS there were significant differencesamong the millet varieties in Minjibir but not in GambawaSuper SOSAT recorded the highest mean LAI of 22 and 26at 6 WAS and 9 WAS respectively in Minjibir and 18 at 6WAS in Gambawa Plant height was not significantly af-fected by N-fertilizer level in Minjibir but significant effectswere observed in Gambawa (Table 2) e plant height atGambawa increases with increase in N-fertilizer levels up to60 kg Nhaminus1 and a further increase in fertilizer reduced theplant heights Super SOSAT recorded the highest mean of190 cm in Minjibir while the local variety recorded highestplant height value of 176 cm in Gambawa In both locationsJirani recorded the lowest mean height of 157 and 143 cm

33 PearlMillet Productivity TotalWaterUse andWater-UseEfficiency e mean grain yield (GY) stalk yield (SY)harvest index (HI) total water use (TWU) and water-useefficiency (WUE) of selected pearl millet varieties grownunder different N-fertilizer levels in two locations over twogrowing seasons are presented in Table 3 N applicationsignificantly affected mean GY in both locations Grain yieldincreased with increasing N-fertilizer rates e highest meanGY of 2273 kg haminus1 at Minjibir and 1714 kg haminus1 at Gambawawas obtained at the application rate of 80 kgNhaminus1e lowestmean GY was recorded at 0 kg Nhaminus1 in both locations erewas no significant difference in GY among the pearl milletvarieties in both locations Stalk yield (SY) of millet varietieswas not significantly affected by N application inMinjibir butthere were significant differences among the varieties inGambawa At 80 kg Nhaminus1 the highest mean SY of 3944 kghaminus1 was recorded at Gambawa e SY increased signifi-cantly with increased N-fertilizer and peaked at 80 kg Nhaminus1then a further increase in N reduced SYe local variety hadthe highest SY with mean values of 4872 kg haminus1 at Minjibirand 4069 kg haminus1 at Gambawa N application did not sig-nificantly affect harvest Index (HI) atMinjibir InMinjibir HIincreased with increased N level and peaked at 60 kg Nhaminus1

and a further increase in N level reduced HI ere weresignificant differences among the N rates for HI in GambawaApplication of 80 kg Nhaminus1 and 100 kg Nhaminus1 recorded thehighest mean HI of 026 each while the lowest mean of 021was recorded for 0 kg Nhaminus1 at Gambawa e variety Jiranihad the highest mean HI of 035 and 029 for Minjibir andGambawa respectively ese values were higher and


significantly different from those of the other pearl milletvarieties used in both locations

Significant differences were observed among theN-fertilizer levels and millet varieties for TWU (Table 3)

TWU value generally decreases with increase in theN-fertilizer level in both locations but it was more evidentin Gambawa than in Minjibir Among the N treatmentsunfertilized plots had the highest TWU in both locations

Table 1 Analysis of physical and chemical properties of the soils (0ndash20 cm depth) at Minjibir and Gambawa

ParametersMinjibir Gambawa

2014 2015 2014 2015Soil texture Sandy loam Sandy Sandy loam Sandy loamParticle size analysis ()Sand 820 906 857 806Silt 65 33 59 33Clay 114 61 85 161Soil pH (H2O) 64 55 62 59EC (1 25 soils water) (dSm) 0031 0044 0031 0049Soil organic carbon (g kgminus1) 196 259 145 201Total nitrogen (g kgminus1) 016 070 012 070Available P (mg kgminus1) 40 45 39 41Available K (cmolkg) 035 037 036 039

121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

012345678910

Total rainfall = 827mmNRD = 34 days Cropping season

2014 growing season

(a)

121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo-

dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

0

2

4

6

8

10Total rainfall = 598mmNRD = 38 days

Cropping season

2015 growing season

(b)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


Cropping season

2014 growing season

(c)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8

10Total rainfall = 500mmNRD = 28 days Cropping season

2015 growing season

(d)

Figure 1 Daily rainfall distribution and evapotranspiration (ETo) during 2014 and 2015 growing seasons (a b) Minjibir and (c d)Gambawa


(2863 and 380mm in Minjibir and Gambawa respec-tively) while the local control had the highest TWUamong the millet varieties in both locations (303 and335mm in Minjibir and Gambawa respectively) Simi-larly Jirani recorded the lowest mean TWU in both lo-cations (250 and 270mm Minjibir and Gambawarespectively) e quadratic function obtained by regres-sion analysis (Figure 2) described the relationship betweengrain yields and TWU across the N rates and pearl milletvarieties in both locationse coefficient of determination(R2) implied the variation of grain yield based on thecontribution of TWU indicated 277 at Minjibir and463 at Gambawa e results suggest higher water de-mand for pearl millet production in Gambawa than inMinjibir

Table 3 further reveals a highly significant effect ofN-fertilizer levels and pearl millet varieties on water-use

efficiency (WUE) in both locations e results show thatN-fertilizer levels increased WUE until it reached 80 kgNhaminus1 after which it slightly decreased in both locationsere was no significant difference for WUE between 60and 80 kg Nhaminus1 in Minjibir In Gambava WUE howeverdiffered significantly between rates of 60 and 80 kg Nhaminus1e highest meanWUE of 82 kg haminus1 mmminus1(Minjibir) and57 kg haminus1mm1 (Gambawa) was obtained at 80 kg Nhaminus1e lowest mean WUE of 54 kg haminus1 mmminus1 in Minjibirand 23 kg haminus1 mmminus1 in Gambawa was recorded at 0 kgN haminus1 WUE differed significantly among the varietieswith Jirani producing the highest mean of 794 and 496 kghaminus1 mmminus1 in Minjibir and Gambawa respectively erewas a strong and positive correlation (R 081 andR 095) between WUE and GY across N-fertilizer ratesand pearl millet varieties in both Minjibir and Gambawa(Figure 3)

Table 3 Effect of N-fertilizer rates and pearl millet variety on grain yield (GY) stalk yield (SY) harvest index (HI) total water use (TWU)and water-use efficiency (WUE) in the semiarid zone of Nigeria

Treatment Minjibir GambawaNitrogen (N) GY SY HI TWU WUE GY SY HI TWU WUE0 kg haminus1 1535 3917 027 2863 54 727 2361 021 320 2320 kg haminus1 1990 4083 028 2835 71 1179 2800 024 307 3940 kg haminus1 2072 4039 030 2848 74 1242 3089 024 303 4260 kg haminus1 2263 4317 031 2833 80 1565 3711 024 304 5280 kg haminus1 2273 4283 030 2829 82 1714 3944 026 302 57100 kg haminus1 2108 4281 029 2850 75 1638 3728 026 301 55LSD (Ple 005) 215lowastlowast 582ns 004ns 251lowast 076lowastlowast 233lowastlowast 735lowastlowast 003lowastlowast 41lowastlowast 081lowastlowastVariety (V)Jirani 1985 2976 035 2501 794 1332 2283 029 270 496Super SOSAT 2042 4611 026 2994 687 1364 3464 024 314 437Local 2094 4872 027 3034 695 1337 4069 02 335 405Grand mean 2040 4153 029 2843 725 1344 3272 024 3062 446LSD (Ple 005) 1526ns 380lowastlowast 002lowastlowast 184lowastlowast 056lowastlowast 129ns 367lowastlowast 002lowastlowast 35lowastlowast 044lowastlowastCV () 184 225 188 16 189 214 262 228 29 223LSD least significant differences of means CV coefficient of variations GY and SY (kgha) TWU (mm) WUE (kg haminus1mmminus1) for final grain yield

Table 2 Effect of N-fertilizer rates and pearl millet variety on soil plant analysis development (SPAD) leaf area index (LAI) and plant heightover two growing seasons in the semiarid zone of Nigeria

Treatment Minjibir Gambawa

Nitrogen (N) SPAD LAI Plant height SPAD LAI Plant height3 WAS 6 WAS 6 WAS 9 WAS cm 3 WAS 6 WAS 6 WAS 9 WAS cm

0 kg haminus1 509 464 18 23 178 462 407 15 20 14220 kg haminus1 502 494 19 23 173 460 433 14 19 15340 kg haminus1 485 484 19 23 178 462 435 15 20 15560 kg haminus1 519 491 20 23 181 484 468 18 20 18980 kg haminus1 542 496 19 24 176 503 474 18 20 156100 kg haminus1 536 492 21 25 180 514 473 17 19 161LSD (Ple 005) 399lowast 239ns 037ns 033ns 947ns 386lowast 209lowastlowast 029lowastlowast 026ns 026lowastVariety (V)Jirani 513 480 16 20 157 491 452 14 19 143Super SOSAT 512 479 22 26 190 471 444 18 20 159Local 522 501 20 25 186 481 449 17 20 176Grand mean 515 487 20 24 178 481 448 16 20 159LSD (Ple 005) 264ns 179lowast 018lowastlowast 018lowastlowast 837lowastlowast 170ns 158ns 017lowastlowast 015ns 019lowastlowastCV () 126 91 226 189 116 86 85 244 198 290LSD least significant differences of means CV coefficient of variations


34 Nitrogen-Use Efficiency and Its Effect on ProductivityFigure 4 depicts nitrogen-use Efficiency (NUE) of pearlmillet varieties in both locations e result shows NUEdecreased with increase in N-fertilizer levelsere were alsosignificant differences in NUE among pearl millet varieties inboth locations In Minjibir Super SOSAT recorded thehighest mean NUE (27plusmn 57 kg grainkg N) at 20 kg Nhaminus1In Gambawa the local variety had the highest mean NUE(235plusmn 49 kg grainkg N) while the lowest mean NUE(21plusmn 5 kg grainkg N) was recorded for Super SOSAT at20 kg Nhaminus1 e quadratic relationship between GY andNUE indicates strong associations (Figure 5) However thecoefficient of determination (R2) which expresses variationof GY by the contribution of NUE suggests 263 yieldvariations at Minjibir and 409 at Gambawa

35 Profitability of DifferentN-Fertilizer Rates on PearlMillete effect of nitrogen fertilizer application and millet va-rieties on the economics of millet production in the semiarid

zone of Nigeria is given in Table 4 Nitrogen fertilizer ap-plication significantly affected the mean total cost of pro-duction (TCP) total revenue (TR) net economic returns(NER) benefit-cost (BC) ratio and break-even yields ofmillet production in both locations e total cost of pro-duction increased directly with the increase in nitrogen ratewhile other economic variables depended on the effect of theN level on productivities e TR increased from 797 and 363USDha (Minjibir and Gambawa respectively) at 0 kg Nhaminus1

to 1078 and 764 USDha (Minjibir and Gambawa respec-tively) at 80 kg Nhaminus1 above which the value dropped InMinjibir the increase in N-fertilizer rate increased NER up to60 kg Nhaminus1 and thereafter NER declined significantly whilein Gambawa the increase in N-fertilizer rate increased NERup to 80 kg Nhaminus1 and thereafter NER declined significantlyLocal variety (597 and 217 US$ha) and Super SOSAT (567and 223 US$ha) in Minjibir and Gambawa respectively hadsimilar NER which were significantly higher than NER ob-tained by Jirani in both locations In Minjibir highest benefit(133) was obtained at 20 kg Nhaminus1 though it was not

y = 05799x2 ndash 3166x + 44892R2 = 0277

Gra

in y

ield

(kg

ha)

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

(a)

y = ndash02291x2 + 13369x ndash 17915R2 = 0463

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

(b)

Figure 2 Quadratic relationship between total water use (TWU) and grain yield (GY) of pearl millet in Minjibir and Gambawa sites Eachdata point represents mean grain yield and TWU across N-fertilizer rates over two growing seasons (2014 and 2015) (a) Minjibir and (b)Gambawa

y = 19882x + 59792R = 0809

0

500

1000

1500

2000

2500

3000

WUE (kghandash1 mmndash1)

1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(a)

y = 26084x + 18164R = 0945


0

500

1000

1500

2000

2500

3000

1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(b)

Figure 3 Linear relationship between pearl millet WUE and grain yield (Y) in Minjibir and Gambawa sites Each data point representsmean grain yield and TWU across N-fertilizer rates over two growing seasons (2014 and 2015) (a) Minjibir and (b) Gambawa


significantly different from 40 kg Nhaminus1 (123) and 60 kgNhaminus1 (127) However in Gambawa the highest B C (064)was obtained at 80 kg Nhaminus1 though it was not significantlydifferent from 60 kg Nhaminus1 (060) 100 kg Nhaminus1 (049) 20 kgNhaminus1 (043) and 40 kg Nhaminus1 (042) Among the varietieswhile there was no significant differences between SuperSOSAT and the local varieties for B C in both locations thetwo were significantly higher than Jirani

Expectedly the BEY increased with an increased level ofnitrogen fertilizer application in both locations Significantdifferences were obtained among the different N applicationrates (Table 4) e control (0 kg Nha) had the lowest (1058and 1073 kgha in Minjibir and Gambawa respectively)BEY while 100 kg Nha had the highest (1467 and 1556 kgha in Minjibir and Gambawa respectively) BEY Eachtreatment had BEY that was significantly higher than that ofN level below itere were no significant differences amongthe millet varieties in both locations for BEY

4 Discussion

is study evaluated the productivity water use andeconomic benefits of pearl millet at different N-fertilizerrates in the semiarid region of Nigeria e two sites arelocated within the Sudan Savanna zone and the totalrainfall and distribution during the two growing seasons(2014 and 2015) differed significantly e analysis of soilchemical properties suggests that soil fertility such as soilorganic carbon (SOC) total N and available phosphoruswere relatively low in both locations but still higher inMinjibir than in Gambawa e low SOC and total Nanalysed from both sites indicated a need for nitrogenfertilizer application for profitable cereal production edifferences in fertility status and rainfall of the two sitesaccounted for the differences in grain and stover yieldsTWU and WUE between the two locations and year eresults agreed with the findings of Sivakumar and Salaam

NU

E (k

g gr

ain

kgN

)

N-fertilizer rate (kgha)

JiraniLocalSuper SOSAT

20 40 60 80 1000

5

10

15

20

25

30

35

(a)



20 40 60 80 100

NU

E (k

g gr

ain

kgN

)

0

5

10

15

20

25

30

35

(b)

Figure 4 Nitrogen-use efficiency of pearl millet cultivars across N-fertilizer rates in Minjibir and Gambawa (mean of 2014 and 2015cropping season) LSD (Ple 005) for nitrogen was 66lowastlowast and variety was 33lowast at Minjibir LSD (Ple 005) for nitrogen was 53lowastlowast and varietywas 31ns at Gambawa (a) Minjibir and (b) Gambawa

0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

0 10 20 30

NUE (kgkgN)

y = ndash1648x2 + 49012x + 1871R2 = 02631

(a)

0

500

1000

1500

2000

2500

3000

0 10 20

Gra

in y

ield

(kg

ha)

NUE (kgkgN)

y = ndash13577x2 + 14148x + 15698R2 = 04088

(b)

Figure 5 Quadratic relationship between NUE and grain yield (GY) of pearl millet in Minjibir and Gambawa sites Each data pointrepresents mean grain yield and NUE across N-fertilizer rates over two growing seasons (2014 and 2015) (a) Minjibir and (b) Gambawa


[11] that millet yields in Sahelian region are driven largelyby the climatic pattern (especially rainfall distribution) andsoil fertility status during growth stages In addition thesandy to sandy loam soils found in both sites promote goodpermeability of roots into the soil e soil texture retainsless water which suggests that good establishment andgrowth of millet can only be favoured by rains that are morefrequent during the cropping season that can at leastpartially meet the continuing high evaporative demandwhile keeping the rooting zone wet and offer the possibilityof a rapid movement of the wetting front towards the storedwater In addition the results at both sites confirmed closeinteraction between water use and nutrient applied ongrowth and yields resulting in a significant increase in GYSY and HI due to different N-fertilizer levels Our studyfound that the application of N at 80 kgha enhances water-use efficiency leading to a greater increase in yield relativeto that in evapotranspiration [12 36 37]

e results of our study show that N requirements formillet may be site-specific with the optimal application rateof 60 kgNhaminus1 for Minjibir and 80 kg Nhaminus1 for GambawaAt the optimal rate of 60 kg Nhaminus1 grain yield increased by32 12 and 8 compared to the applied rate of 0 20and 40 kg Nhaminus1 respectively in Minjibir Similarly at theoptimal rate of 80 kg Nhaminus1 grain yield increased by 5831 28 and 8 compared to the applied rate of 0 20 40and 60 kg Nhaminus1 respectively in Gambawa e optimal Nrate observed at Gambawa was compared favourably withthat reported in the study conducted in southern Indiawhich indicated that higher growth yield attributes andyield of pearl millet can be obtained by fertilizing the cropwith 80 kg Nha [38] However a study in a similar en-vironment in West Africa [25] reported a response at 30 kgNha and a significant plant population by N-fertilizerinteraction as well as N-fertilizer by rainfall interaction Asobserved from this study blanket N rates should not be

applied by farmers in all locations even within the sameagroecological zone but rather the N application should bebased on the knowledge of inherent soil fertility and rainfallamount and distribution e results are in agreement withmany other studies including that of Joshi et al [38] whodemonstrated a parabolic relationship between N and grainyield which implies that when N rate surpassed a certainthreshold the grain yield greatly decreased However thestudy found that under certain conditions increased Napplication rates may reduce TWU thereby increasingWUE as was clearly observed in Gambawa WUE did notsignificantly differ between N rates of 80 and 100 kg haminus1which indicates that excessive N application had nofavourable effect on WUE e maximum WUE corre-sponds to the maximum grain yield in both locationswhich implies that the higher WUE by pearl millet cropwould result in higher yield gain with less water demands[11] Meanwhile when evapotranspiration is less affectedby management any factor that increases yield will increaseWUE In addition N-fertilizer could be seen as beneficial tothe rapid early growth of leaves leading to higher SY acrossdifferent N-fertilized treatments compared to unfertilizedN treatment e direct evaporation from the soil on themillet field varied between 35 and 45 of rainfall with thehigher proportions occurring in the lower rainfall [39]us strategies such as the use of fertilizer which canpromote rapid early growth can contribute to the re-duction of soil evaporative losses and increasedWUE NUEsignificantly decreased as a linear function with increasingN levels with the application of N at 20 kg Nhaminus1 having thehighest NUE values at the application rate of 20 kg Nhaminus1is result was in agreement with several studies reportedon various crops eg sorghum [12 40] millet [41] andmaize [42] is shows that higher NUE is recorded atlower rates of N application than higher rates of N ap-plication is agrees with the findings that NUE in pearl

Table 4 Economic analysis of pearl millet varieties under N-fertilizer application in the semiarid zone of Nigeria (mean of 2014 and 2015growing seasons)

TreatmentMinjibir Gambawa

TCP TR NER B C BEY TCP TR NER B C BEY(US$ haminus1) (kg haminus1) (US$ haminus1) (kghaminus1)

Nitrogen (N)0 kg haminus1 371 797 426 115 1058 337 363 26 008 107320 kg haminus1 413 965 552 133 1177 376 537 161 043 119940 kg haminus1 440 986 546 123 1254 402 568 166 042 128360 kg haminus1 471 1077 610 127 1344 437 701 264 060 139580 kg haminus1 496 1078 582 116 1415 466 764 298 064 1488100 kg haminus1 514 1014 500 097 1467 487 722 236 049 1556LSD (Ple 005) 83lowastlowast 923lowastlowast 848lowast 016lowastlowast 231lowastlowast 72lowastlowast 113lowastlowast 106lowastlowast 023lowastlowast 205lowastlowast

Variety (V)Jirani 449 891 442 098 1280 417 553 136 031 1332Super SOSAT 451 1018 567 125 1285 418 641 223 052 1329Local 453 1050 597 132 1292 417 634 217 050 1336Grand mean 451 986 535 118 1286 417 609 192 044 1332LSD (Ple 005) 59ns 643lowastlowast 589lowastlowast 011lowastlowast 167ns 41 522lowastlowast 485lowastlowast 011lowastlowast 132 nsCV () 32 160 270 254 32 24 257 41 388 26TCP total cost of production TR total revenue (grain and stalk yields) NER net economic return B C benefit-cost ratio BEY break-even yield at currentprice (kgha) LSD least significant differences of means CV coefficient of variation


millet declines because of an increase in rates of N ap-plication [43 44] e NUE may be increased if farmersapply N in 3-4 splits such that N is applied at several peakdemands and wastage in the form of leakage is minimisede economic analysis revealed low TCP TR NER and B C for unfertilized plots compared to the different N-fer-tilizer levels in both locations erefore to increase theproductivities of pearl millet farmers input and judicioususe of the inputs are necessary Low input specifically lowN-fertilizer input to pearl millet production in the semiaridzones may result in low labour productivity for farmersparticularly in a drier area (eg Gambawa site) due to lownutrients in the soil (eg organic carbon total nitrogenand available phosphorus) Our results suggest that farmersin Minjibir can profitably grow pearl millet between N rateof 20 and 60 kg haminus1 leading to the same benefit-cost ratio(B C 1 133 to 1 127) while in Gambawa it can beextended to 80 kg Nhaminus1 (B C 1 043 to 1 064) isimplies that farmers in Minjibir would make US$ 13 onevery US$ 1 invested by applying N-fertilizer at 20 kg Nhaminus1

and US$ 127 on every US$ 1 by applying N-fertilizer at60 kg Nhaminus1 It is therefore necessary to increase the NUEof pearl millet especially at the higher N application rateAgronomic strategies such as plant population number ofsplit fertilizer application and type of N-fertilizer appliedshould be investigated to increase the NUE of applied N inpearl millet cultivation e work of other researchers [25]has shown that N application and high plant density in-creased millet grain yield four- to fivefold e break-evenyield at the current price indicates that farmers mustproduce significantly higher grain than 1000 kghaminus1 evenunder no fertilizer input is implies that majority offarmers are producing at a loss considering that the presentaverage yield of pearl millet in Nigeria is 801 kgha [2] to850 kgha [45]

5 Conclusion

Our study has shown that N fertilization affected thegrowth grain yield stalk yield TWU WUE and NUE ofthe two improved and local pearl millet varieties tested inboth Minjibir and Gambawa e economic analysis alsoshowed that TR NER and B C were significantly affectedby nitrogen fertilizer application as well as pearl milletvarieties Dissemination campaigns of improved pearlmillet production technologies should be encouraged toincrease adoption and pearl millet on-farm yield since anaverage farmer may presently be producing at less than thebreak-even yields ere were significant differences ingrain and stalk yields of the pearl millet varieties testedbetween the two locations irrespective of N-fertilizer ratesapplied is is probably due to differences in total rainfalland distribution and the inherent soil fertility in those twolocations ere was a strong interaction between water useand nitrogen supply on pearl millet varieties resulting in anincrease in WUE It is therefore clear that the use ofchemical fertilizers particularly nitrogen is advantageousfor the profitability of pearl millet production in thesemiarid zone by applying appropriate dose in order to

meet the crop and soil demand for higher productivityBased on the study we therefore recommend that farmersin Minjibir and other similar wetter areas of semiarid couldapply N between 40 and 60 kg haminus1 for pearl milletMeanwhile at Gambawa the application rates of 60 and80 kg Nhaminus1 is recommended for pearl millet for higherproductivity and profitability

Data Availability

e raw data for the experiment are available as interna-tional public goods and can be made available on request tothe International Crops Research Institute for the Semi-AridTropics (a member of the CGIAR)

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

e authors would like to thank the International CropsResearch Institute for the Semi-Arid Tropic (ICRISAT) forproviding institutional funding to conduct the experimentalwork under the CGIAR research program GLDC is re-search was funded by Bill and Melinda Gates Foundation inthe HOPE 2 project which was the precursor to AVISAproject grant number OPP1198373

References

[1] H A Ajeigbe F M Akinseye F M Akinseye A KunihyaA I Abdullahi and A Y Kamara ldquoResponse of pearl millet(Pennisetum glaucum L) to plant population in the semi-aridenvironments of Nigeriardquo Net Journal of Agricultural Sciencevol 7 no 1 pp 13ndash22 2019

[2] FAOSTAT Food and agriculture organization statistics)ldquocrops area and production of pearl millet 2018

[3] M Sathya N K Vinodhana and P Sumathi ldquoHierarchialclustering of pearl millet (Pennisetum glaucum (L) R Br)inbreeds for morpho-physiological traitsrdquo InternationalJournal of Current Microbiology and Applied Sciences vol 2no 12 pp 647ndash653 2013

[4] B M Mweu T E Akuja and M W Mburu ldquoPerformance ofsix pearl millet (pennisetum glaucum (L) R Br) varieties in thesemindasharid Kitui county of Kenyardquo International Journal ofAgricultural Research and Review vol 4 no 3 pp 514ndash5212016

[5] R K Pandey J W Maranville and Y Bako ldquoNitrogenfertilizer response and use efficiency for three cereal crops inNigerrdquo Communications in Soil Science and Plant Analysisvol 32 no 9-10 pp 1465ndash1482 2001

[6] Q Miguel and J L Gabriel ldquoApproaches for increasing ni-trogen and water use efficiency simultaneouslyrdquo Global FoodSecurity vol 9 pp 29ndash35 2016

[7] F R Bidinger and C T Hash ldquoPearl milletrdquoldquoPearl milletrdquo inIntegration of Physiology and Molecular Biology in PlantBreeding H T Nguyen Ed Marcel- Decker New York NYUSA 2003

[8] V K Manga and A Kumar ldquoCultivar options for increasingpearl millet productivity in arid regionsrdquo Indian Journal of


Fundamental and Applied Life Sciences vol 1 no 2pp 200ndash208 2011

[9] S C Mason M Nouri and S Pale ldquoPearl millet productionpractices in semi-arid West Africa a reviewrdquo ExperimentalAgriculture vol 51 no 4 pp 501ndash521 2015

[10] L Stroosnijder and W B Hoogmoed ldquoCrust formation onsandy soils in the Sahel II Tillage and its effect on the waterbalancerdquo Soil and Tillage Research vol 4 no 4 pp 321ndash3371984

[11] M V K Sivakumar and S A Salaam ldquoEffect of year andfertilizer on water-use efficiency of pearl millet (Pennisetumglaucum) in Nigerrdquo lte Journal of Agricultural Sciencevol 132 no 2 pp 139ndash148 1999

[12] H A Ajeigbe F M Akinseye A Kunihya and J JonahldquoProductivity and water use efficiency of sorghum [sorghumbicolor (L) moench] grown under different nitrogen appli-cations in Sudan savanna zone Nigeriardquo InternationalJournal of Agronomy vol 2018 Article ID 7676058 11 pages2018

[13] T R Sinclair and T W Rufty ldquoNitrogen and water resourcescommonly limit crop yield increases not necessarily plantgeneticsrdquo Global Food Security vol 1 no 2 pp 94ndash98 2012

[14] W P Piekielek and R H Fox ldquoUse of chlorophyll meter topredict side dress N requirements for maizerdquo AgronomyJournal vol 84 no 1 pp 59ndash65 1992

[15] H Shuangjie C Zhao Y Zhang and C Wang ldquoNitrogen useefficiency in ricerdquo in Nitrogen in Agriculture Update-sIntechOpen London UK 2018

[16] A Y Kamara S U Ewansiha and A Menkir ldquoAssessment ofnitrogen uptake and utilization in drought tolerant and Strigaresistant tropical maize varietiesrdquo Archives of Agronomy andSoil Science vol 60 no 2 2014

[17] M J Hawkesford S Kopriva and L J De Kok Eds PlantEcophysiologySpringer Berlin Germany 2014

[18] M K Schenk ldquoNutrient efficiency of vegetable cropsrdquo ActaHorticulturate vol 700 no 700 pp 21ndash34 2006

[19] J S Samra and P D Sharma ldquoFood security-Indian sce-nariordquoldquoFood security-Indian scenariordquo in Potassium Role andBenefits in Improving Nutrient Management for Food Pro-duction Quality and Reduced Environmental DamagesM S Brar and S S Mukhopadhyaya Eds pp 15ndash43 eInternational Potash Institute Orissa India 2011

[20] H A Ajeigbe F M Akinseye P C S Traore et al ldquoIncreasingthe productivity of sorghum farmers in the Sudan Savannah ofNigeria effect of access to improved technology and marketrdquoin Proceedings of the Conference Tagged ldquoSorghum in the 21stCenturyrdquo Century City Conference Centre Cape Town SouthAfrica April 2018

[21] E A Ali ldquoGrain yield and nitrogen use efficiency of pearlmillet as affected for plant density nitrogen rate and splittingin sandy soilrdquo American-eurasian Journal of Agriculture ampEnvironmental Sciences vol 7 no 3 pp 327ndash335 2010

[22] ICRISAT Sorghum Patancheru (AP) intrsquol crops researchInstitute for the semi-arid tropics 2009

[23] T L Fan B A Stewart Y G Wang J J Luo and G Y ZhouldquoLong-term fertilization effects on grain yield water-use ef-ficiency and soil fertility in the dry land of loess plateau inChinardquo Agriculture Ecosystems amp Environment vol 106no 4 pp 313ndash329 2005

[24] C M Cossani G A Slafer and R Savin ldquoNitrogen and wateruse efficiencies of wheat and barley under a mediterraneanenvironment in Cataloniardquo Field Crops Research vol 128pp 109ndash118 2012

[25] A Bationo C B Christianson and W E Baethgen ldquoPlantdensity and nitrogen fertilizer effects on pearl millet pro-duction in Nigerrdquo Agronomy Journal vol 82 no 2pp 290ndash295 1990

[26] FAO ldquoWorld soil resources an explanatory note on the FAOworld soil resources map at 125000000 scale 1991 Rev1993rdquo in World Soil Resources Reports 66FAO Rome Italy1993

[27] G Hoogenboom P W Wilkens and G Y Tsuji ldquoDSSATversion 3 (4)rdquo in International Consortium for AgriculturalSystems Application pp 234-235 University of HawaiiHonolulu HI USA 1999

[28] J Doorenbos and A H Kassam Yield Response to WaterIrrigation and Drainage Report Food and Agriculture Or-ganization of the United Nations Rome Italy 1979

[29] R G Allen L S Pereira D Raes and M Smith CropEvapotranspirationmdashGuidelines for Computing Crop WaterRequirements FAO Irrigation and Drainage Paper 56 Foodand Agriculture Organization Rome Italy 1998

[30] Y Kuslu U Sahin T Tunccedil and FM Kiziloglu ldquoDeterminingwater-yield relationship water use efficiency seasonal cropand pan coefficient for alfalfa in a semiarid region with highaltituderdquo Bulgarian Journal of Agricultural Science vol 16no 4 pp 482ndash492 2010

[31] R Prasad Enhancing Nutrient Use Efficiency EnvironmentalBenign Strategiesrdquo Souvenir 67-74 e Indian Society of SoilScience New Delhi India 2009

[32] CIMMYT-International Maize and Wheat ImprovementCenter From Agronomic Data to Farmer RecommendationsAn Economics Training Manualrdquo Completely Revised EditionMexico DF Mexico 1988

[33] H A Ajeigbe and B B Singh ldquoIntegrated pest managementin cowpea effect of Time and frequency of insecticide ap-plication on productivityrdquo Crop Protection vol 25 no 9pp 920ndash925 2006

[34] R Kanton P Asungre E Y Ansoba et al ldquoEvaluation of pearlmillet varieties for adaptation to the semi-arid agro-ecology ofnorthern Ghanardquo Journal of Agriculture and Ecology ResearchInternational vol 3 no 1 pp 1ndash11 2015

[35] K A Gomez and A A Gomez Statistical Procedures forAgricultural Research John Wiley and sons New York NYUSA 2nd edition 1984

[36] J T Ritchie ldquoEfficient water use in crop production dis-cussion on the generality between biomass production andevapotranspirationrdquo in Limitations to Efficient Water Use inCrop Production pp 29ndash44 American Society of AgronomyMadison WI USA 1983

[37] H A Ajeigbe F M Akinseye A Kunihya and J JonahldquoSorghum yield and water use under Phosphorus applicationsin Sudan Savanna zone of NigeriardquoGlobal Advanced ResearchJournal of Agricultural Science vol 7 no 3 pp 245ndash257 2018

[38] M P Joshi R M Pankhaniya and N K MohammadildquoResponse of pearl millet (Pennisetum glaucum L) to levelsand scheduling of nitrogen under south Gujarat conditionrdquoInternational Journal of Chemical Studies vol 6 no 1pp 32ndash35 2018

[39] J Fechter B E Allison M V K Sivakumar R R van derPloeg and J Bley ldquoAn evaluation of the SWATRER andCERES-Millet models for southwest NigerrdquoldquoAn evaluation ofthe SWATRER and CERES-Millet models for southwestNigerrdquo in Soil Water Balance in the Sudano-Sahelian Zone(Proc Niamey Workshop February 1991)M V K Sivakumar J S Wallace C Renard and C GirouxEds pp 505ndash513 IAHS Publications Wallingford UK 1991


[40] S S J Buah J M Kombiok and L N Abatania ldquoGrainsorghum response to NPK fertilizer in the Guinea Savanna ofGhanardquo Journal of Crop Improvement vol 26 no 1pp 101ndash115 2012

[41] N Gupta A K Gupta V S Gaur and A Kumar ldquoRela-tionship of nitrogen use efficiency with the activities of en-zymes involved in nitrogen uptake and assimilation of fingermillet genotypes grown under different nitrogen inputsrdquo lteScientific World Journal vol 2012 Article ID 62573110 pages 2012

[42] M M Hefny and A A Aly ldquoYielding ability and nitrogen useefficiency in maize inbred lines and their crossesrdquo Interna-tional Journal of Agricultural Research vol 3 no 1 pp 27ndash392008

[43] O Diouf Y C Brou M Diouf et al ldquoResponse of pearl milletto nitrogen as affected by water deficitrdquo Agronomie vol 24no 2 pp 77ndash84 2004

[44] N Maman S C Mason and D J Lyon ldquoNitrogen rate in-fluence on pearl millet yield nitrogen uptake and nitrogenuse efficiency in Nebraskardquo Communications in Soil Scienceand Plant Analysis vol 37 no 1-2 pp 127ndash141 2006

[45] NAERLS ldquoAgricultural performance survey 2017 wet seasonin Nigeriardquo in National Report National Agricultural Ex-tension and Liaison Services (NAERLS) and Federal Depart-ment of Agricultural Extension (FDAE)NAERLS AbujaNigeria 2017


active radiation (PAR) water and nutrients especially Nresulting in a significant increase in grain and stover yields[9]

Despite the fact that the crop can be grown in low rainfallbelt studies have shown that millet production in WestAfrica is primarily constrained by limited water supply thatdetermines the amount of water used for growth andproductivity [10 11] Rainfall and soils are the major en-vironmental resources that merit detailed analysis in theefforts to increase millet production [11] e inadequatesupply of plant nutrients by most farmers restricts the ef-ficient use of limited rainfall and this results in unstable lowproductivity of millet [5] Similarly studies have shown thatgreater water-use efficiency could be achieved through ef-ficient use of fertilizers [11 12] without underestimating therole of plant genetics [13] Additionally demand for food bythe growing population in Nigeria will require that we in-crease resource-use efficiency of water and nutrient forcereal crops including pearl millet Among the nutrients Nis the most limiting nutrient for cereal production on de-graded semiarid soils although P is also a major problem [5]Monitoring plant N to ensure an adequate supply for plantrequirements is necessary to have optimum growth im-proved NUE and to reduce N losses [14] In rainfedcropping systems adapting N management to water con-straints may help to mitigate N losses and therefore increaseNUE In its simplest definition NUE is the grain yield perunit of supplied N [15] It is affected by several factors andprocesses including N uptake translocation assimilationand remobilization [16] NUE is an important target for cropimprovement [17] though crop-specific managementstrategies may be required Improvement of NUE is a way toefficiently use inorganic fertilizer which is an essentialprerequisite for the expansion of crop production intomarginal lands with low nutrient availability [18] e un-derstanding of NUE in pearl millet across the growing areasis very important for economic environmental and pro-ductivity reasons [19] is is due to unbalanced applicationand high cost of fertilizer or fertilizer availability whichconstitute a big constrain to resource-poor farmers inNigeria [20] In addition with the advocacy of improvedproduction practices and cultivars the use of nitrogenfertilizers is increasing quantitatively but responsive yieldsto N are substantially fading over the years in all crops [19]including pearl millet [21]us balancing the N rate WUEand yield is an important problem in dryland farmingsystems Classical reviews of fertilizers and efficient use ofwater for maize [6] concluded that in most cases when thewater supply is fixed any management factor that increasesyield would increase water-use efficiency It was reported in[11] that under Sahelian conditions 84 increase ofWUE inmillet (grain yield per mm rain) is due to the application ofmineral fertilizers e application of N increases WUE by15 and grain yield by 400 kg over control for sorghum cropcultivated under rainfed condition [22] Although im-provements in yield may be brought about by judiciousapplications of fertilizer a better understanding of inter-actions among precipitation fertilization and crop pro-duction is essential for efficient utilization of water resources

and N-fertilizers [23] A good plant N nutritional statusenhances millet tolerance to drought and enhances mor-phological traits thereby increasing yields [24] With av-erage or above rainfall N application and high plant densityincreased millet grain yield four- to fivefold Nitrogen ap-plication increased stover production by 33 in a dry yearand by 100 in a wetter year [25] N supply of sim30 kg Nha intwo split applications achieved good yields in average andwet years with only a small yield reduction in the droughtyear [25] A moderate increase of N supply for sorghum wasreported to improve water-use efficiency (WUE) undersemiarid environments [12] To attain high stable yields ofpearl millet by smallholder farmers that will deliver higherprofitability in the region would therefore require combi-nations of improved varieties optimum amounts of fertil-izer and good cultural management practices for efficientutilization of limited water ere is limited information onthe response of new improved diverse millet varieties toapplied N in terms of grain yield (GY) total water use(TWU) nitrogen-use efficiency (NUE) and water-use effi-ciency (WUE) e objectives of the trial were to assess thedirect effect of nitrogen application and varieties on pro-ductivity and water- and nitrogen-use efficiency of pearlmillet and to identify optimal N-fertilizer rate for higherprofitability of pearl millet production relative to the studyareas

2 Materials and Methods

21 Description of the Experimental Sites e experimentswere conducted during the 2014 and 2015 growing seasons attwo sites within the semiarid region of Nigeria e firstlocation was ICRISAT research field situated within theInstitute for Agricultural Research (IAR) station Wasaivillage Minjibir Local Government Area of Kano State(latitude 1217degN and longitude 865degE 455m ASL) while thesecond location was within farmersrsquo field in GambawaGumel Local Government Area of Jigawa State (latitude12625degN and longitude 9325degE 370m ASL) Both sites arelocated in the Sudan Savanna agroecological zone wheresoils are mainly sandy and loamy of low fertility [26] etrials were conducted in different parts of the research farm(Minjibir) and farmers field (Gambawa) in the 2 yearsUndisturbed soil samples were randomly taken at a depth(0ndash20 cm) prior to sowing for each location in both growingseasons Soil samples were analysed at the Soil ScienceDepartment Laboratory Bayero University Kano Nigeriaey were analysed for particle size distribution organiccarbon (OC) pH and other chemical properties as describedin [27]

22 Experimental Design e experiment was a split plotdesign with four replicationsemain plot had six nitrogen(N) fertilizer levels (0 20 40 60 80 and 100 kg haminus1) andthe subplots randomised within the main plots had threepearl millet varieties (Jirani Super SOSAT and local con-trol) e details of the varieties used (Jirani Super SOSATand local) have been described by Ajeigbe et al [1]e gross






TWU KcETo (1)


Δ + c 1 + 034u2( 1113857 (2)




WUE Y

TWU (3)



NUE Yf minus Yc

Na

(4)






3 Results
















121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

012345678910


2014 growing season

(a)

121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo-

dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

0

2

4

6

8


Cropping season

2015 growing season

(b)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


Cropping season

2014 growing season

(c)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


2015 growing season

(d)

















y = 05799x2 ndash 3166x + 44892R2 = 0277

Gra

in y

ield

(kg

ha)

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

(a)

y = ndash02291x2 + 13369x ndash 17915R2 = 0463

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

(b)


y = 19882x + 59792R = 0809

0

500

1000

1500

2000

2500

3000


1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(a)

y = 26084x + 18164R = 0945


0

500

1000

1500

2000

2500

3000

1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(b)





4 Discussion


NU

E (k

g gr

ain

kgN

)



20 40 60 80 1000

5

10

15

20

25

30

35

(a)



20 40 60 80 100

NU

E (k

g gr

ain

kgN

)

0

5

10

15

20

25

30

35

(b)


0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

0 10 20 30

NUE (kgkgN)

y = ndash1648x2 + 49012x + 1871R2 = 02631

(a)

0

500

1000

1500

2000

2500

3000

0 10 20

Gra

in y

ield

(kg

ha)

NUE (kgkgN)

y = ndash13577x2 + 14148x + 15698R2 = 04088

(b)














5 Conclusion



Data Availability




Acknowledgments


References






















































TWU KcETo (1)


Δ + c 1 + 034u2( 1113857 (2)




WUE Y

TWU (3)



NUE Yf minus Yc

Na

(4)






3 Results
















121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

012345678910


2014 growing season

(a)

121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo-

dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

0

2

4

6

8


Cropping season

2015 growing season

(b)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


Cropping season

2014 growing season

(c)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


2015 growing season

(d)

















y = 05799x2 ndash 3166x + 44892R2 = 0277

Gra

in y

ield

(kg

ha)

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

(a)

y = ndash02291x2 + 13369x ndash 17915R2 = 0463

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

(b)


y = 19882x + 59792R = 0809

0

500

1000

1500

2000

2500

3000


1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(a)

y = 26084x + 18164R = 0945


0

500

1000

1500

2000

2500

3000

1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(b)





4 Discussion


NU

E (k

g gr

ain

kgN

)



20 40 60 80 1000

5

10

15

20

25

30

35

(a)



20 40 60 80 100

NU

E (k

g gr

ain

kgN

)

0

5

10

15

20

25

30

35

(b)


0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

0 10 20 30

NUE (kgkgN)

y = ndash1648x2 + 49012x + 1871R2 = 02631

(a)

0

500

1000

1500

2000

2500

3000

0 10 20

Gra

in y

ield

(kg

ha)

NUE (kgkgN)

y = ndash13577x2 + 14148x + 15698R2 = 04088

(b)














5 Conclusion



Data Availability




Acknowledgments


References




















































3 Results
















121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

012345678910


2014 growing season

(a)

121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo-

dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

0

2

4

6

8


Cropping season

2015 growing season

(b)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


Cropping season

2014 growing season

(c)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


2015 growing season

(d)

















y = 05799x2 ndash 3166x + 44892R2 = 0277

Gra

in y

ield

(kg

ha)

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

(a)

y = ndash02291x2 + 13369x ndash 17915R2 = 0463

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

(b)


y = 19882x + 59792R = 0809

0

500

1000

1500

2000

2500

3000


1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(a)

y = 26084x + 18164R = 0945


0

500

1000

1500

2000

2500

3000

1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(b)





4 Discussion


NU

E (k

g gr

ain

kgN

)



20 40 60 80 1000

5

10

15

20

25

30

35

(a)



20 40 60 80 100

NU

E (k

g gr

ain

kgN

)

0

5

10

15

20

25

30

35

(b)


0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

0 10 20 30

NUE (kgkgN)

y = ndash1648x2 + 49012x + 1871R2 = 02631

(a)

0

500

1000

1500

2000

2500

3000

0 10 20

Gra

in y

ield

(kg

ha)

NUE (kgkgN)

y = ndash13577x2 + 14148x + 15698R2 = 04088

(b)














5 Conclusion



Data Availability




Acknowledgments


References
























































121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

012345678910


2014 growing season

(a)

121

129

131

145

153

161

169

177

185

193

201

209

217

225

233

241

249

257

265

273

281

289

297

Rain

fall

(mm

)

ETo-

dai

ly ev

apot

rans

pira

tion

(mm

)

0

20

40

60

80

100

Julian days

Rain (mm)

ETo (mmday)

0

2

4

6

8


Cropping season

2015 growing season

(b)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


Cropping season

2014 growing season

(c)

121

130

139

148

157

166

175

184

193

202

211

220

229

238

247

256

265

274

283

292

301

ETo

- dai

ly ev

apot

rans

pira

tion

(mm

)

Dai

ly ra

infa

ll (m

m)

0

20

40

60

80

100

Julian days

Rainfall

ETo

0

2

4

6

8


2015 growing season

(d)

















y = 05799x2 ndash 3166x + 44892R2 = 0277

Gra

in y

ield

(kg

ha)

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

(a)

y = ndash02291x2 + 13369x ndash 17915R2 = 0463

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

(b)


y = 19882x + 59792R = 0809

0

500

1000

1500

2000

2500

3000


1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(a)

y = 26084x + 18164R = 0945


0

500

1000

1500

2000

2500

3000

1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(b)





4 Discussion


NU

E (k

g gr

ain

kgN

)



20 40 60 80 1000

5

10

15

20

25

30

35

(a)



20 40 60 80 100

NU

E (k

g gr

ain

kgN

)

0

5

10

15

20

25

30

35

(b)


0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

0 10 20 30

NUE (kgkgN)

y = ndash1648x2 + 49012x + 1871R2 = 02631

(a)

0

500

1000

1500

2000

2500

3000

0 10 20

Gra

in y

ield

(kg

ha)

NUE (kgkgN)

y = ndash13577x2 + 14148x + 15698R2 = 04088

(b)














5 Conclusion



Data Availability




Acknowledgments


References
































































y = 05799x2 ndash 3166x + 44892R2 = 0277

Gra

in y

ield

(kg

ha)

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

(a)

y = ndash02291x2 + 13369x ndash 17915R2 = 0463

200 250 300 350 400

TWU (mm)

0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

(b)


y = 19882x + 59792R = 0809

0

500

1000

1500

2000

2500

3000


1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(a)

y = 26084x + 18164R = 0945


0

500

1000

1500

2000

2500

3000

1 3 5 7 9 11

Gra

in y

ield

(kgh

andash1)

(b)





4 Discussion


NU

E (k

g gr

ain

kgN

)



20 40 60 80 1000

5

10

15

20

25

30

35

(a)



20 40 60 80 100

NU

E (k

g gr

ain

kgN

)

0

5

10

15

20

25

30

35

(b)


0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

0 10 20 30

NUE (kgkgN)

y = ndash1648x2 + 49012x + 1871R2 = 02631

(a)

0

500

1000

1500

2000

2500

3000

0 10 20

Gra

in y

ield

(kg

ha)

NUE (kgkgN)

y = ndash13577x2 + 14148x + 15698R2 = 04088

(b)














5 Conclusion



Data Availability




Acknowledgments


References




















































4 Discussion


NU

E (k

g gr

ain

kgN

)



20 40 60 80 1000

5

10

15

20

25

30

35

(a)



20 40 60 80 100

NU

E (k

g gr

ain

kgN

)

0

5

10

15

20

25

30

35

(b)


0

500

1000

1500

2000

2500

3000

Gra

in y

ield

(kg

ha)

0 10 20 30

NUE (kgkgN)

y = ndash1648x2 + 49012x + 1871R2 = 02631

(a)

0

500

1000

1500

2000

2500

3000

0 10 20

Gra

in y

ield

(kg

ha)

NUE (kgkgN)

y = ndash13577x2 + 14148x + 15698R2 = 04088

(b)














5 Conclusion



Data Availability




Acknowledgments


References





























































5 Conclusion



Data Availability




Acknowledgments


References


















































productivity,water-andnitrogen-useefficiency,and...

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