Agronomy

COMPARATIVE ANALYSIS OF PRODUCTIVITY AND PROFITABILITY BETWEEN

INTERCROPPED AND MONOCROPPED SUGARCANE IN THE PHILIPPINES

Teodoro C. Mendoza Department o f Agronomy, University o f the Philippines

at Los Banos, College, Laguna 3720, Phil ippines

ABSTRACT

The changes in productivity and profitability arising from the applica- tion of different levels of fertilizer and intercropping with legumes and non- legumes were evaluated in field experiments at Los Banos, Laguna, Philip- pines. The mixture - sugarcane + legume (soybean, mungbean, peanut) was rnore productive and profitable than sugarcane + non-legume but the overall productivity with intercropping was higher only under low to average levels of input for sugarcane pure culture, not in the high-input application. Low-statured intercrops with short maturing times preferentially direct photosynthesis towards vegetative tissues. Since labour and material costs were spread over two crops, returns on labour and material costs, and finally benefit-cost ratio wece, higher in compatible sugarcane intercropping systems. While cash adtaintage can be realised with sugarcane + legume intercropping, increased fertilizer and cultivation inputs can equal or even surpass the aggregate revenue of the most profitable intercropping system.

INTRODUCTION

Crop diversification and increasing sugarcane productivity through improved management are two general strategies which may make sugarcane farming still a viable enterprise under Philippine conditions.

Crop diversification, which includes polyculture and intensive use of by- products, has the characteristics of spreading the risk and increasing the productivity and income of the farm. The other features of polyculture include built-in balanced nutritional suppiy86f energy and protein (Gomez3). Polyculture has also been shown to increase water utilization efficiency, and to provide inexpensive weed control (Bantilan2) and insect pest control (Rarosl0), and to improve soil fertility (Agboola and ~ a ~ a m i ' ) . Greater efficiency in terms of light interception resulting in significantly higher total biomass production (Evans4; Nadal and Hardwood7; Syarifuddin12) is one supreiile advantage of polyculture from the agro-ecological standpoint.

Viewed from the socio-economic standpoint, introducing other enterprises into a one-year crop like sugarcane offers the following advantages: (a) a mid-year cash

Keywords: Intercropping, biological productivity, profitability

TEODORO C . MENDOZA 97

in-flow on the part of the small farmer, (b) utilization of partially used farmers' labour during off-milling season, (c) for large-scale~lantation, allowing workers to plant an intercrop serves as an incentive which may be more meaningful than wage adjustment, (d) minimize the impact of any sudden drop of sugar price.

Increasing sugarcane productivity through improved management is the other strategy. Sugar yield-increasing practices have been extensively worked out in the past. In addition to variety, irrigation and cultivation, fertilizer and weed control practices have been established as critical inputs in maximizing sugar yield (~osario"; Tetangco13). This strategy, however, considers that the farmer is financially able to procure the input and technically equipped to manage the correct use of the input.

This study was conducted to determine the apparent biomass productivity (divided into botanic and economic yield) of the two production strategies and to compare the profitability of the various intercrop combinations and improved sugarcane crop husbandry practices.

MATERIALS AND METHODS

Two field experiments were conducted at the Central Experiment Station (C.E.S.), U.P. at Los Banos, College, Laguna from January 1984 to January 1985. These were sugarcane intercropping and yield maximization.

Sugarcane intercropping Two groups of short duration field crops were selected for evaluation - (a) legumes - mungbean, soybean and peanut (b) energy (starch) crops - corn, sweet potato, and cassava

These cash crops were intercropped in 2 spatial arrangements. The first was a double row scheme consisting of 2 rows of cane spaced at 0.5 m with 2.0 m between the double rows. Intercrops were planted in the larger 2.0 m intervals. The second involved row-to-row intercropping with cane planted at 1.5 m spacing.

Yield maximization

Yield maximization was pursued by using improved cultivar (Phil 60-07) grown at various levels of weed control and fertilizer inputs. The rates of application N, P20, and K20 in kg/ha were - F1 75-75-150; F2 150-75-200; F3 250-75-300; F, 350-75-400.

Two spacings (1.0 and 1.5 m) were included in the study representing non- mechanized and mechanized operations, respectively.

General Currently recommended varieties were used as test materials in all the experi-

ments. The specific cultivars used for the various crops were: Sugarcane - Phil 66-07; Corn - IPB Var 1; Cassava - Lakan; Sweet Potato - Kinabakab; Mungbean - Pag- asa 3; Soybean - UP1 Sy-2; Peanut - UP1 Pn-2.

The fertilizer rates (N, P20,, K20) for sugarcane and the intercrops were: Sugarcane - 150-75-200; Corn - 60-30-30; Cassava + Sweet Potato - 30-30-60; Mungbean + Soybean + Peanut - 30-30-30. The intercrops were planted at the same time as the cane.

Human edible and non-edible yield components were separated for biomass productivity analysis. All yields were adjusted to 14% moisture content.

In both experiments, biomass productivity was assessed. Yield was classified into botanic yield (BY) and economic yield (EY). Using standard values which Pining de Vries9 derived to synthesize proteidfats, EY for all crops was adjusted. The general formula used for adjusting economic yield (AEY) was:

AEY = EY - (EY x % protein + EY x % fat) + EY x g-glu equivalent for protein synthesis x % prot + EY x g-glu equivalent for fat synthesis x % fat The constants used for g-glu equivalents for protein and fat synthesis were 2.045

and 3.03, respectively (Pining de Vriesg). The EY adjusted to (CH20) level was then added to BY to get the corrected total dry matter yields. The heating values of the biomass produced for each crop were also noted. A constant of 3700 kcal/kg biomass was used after adjusting the moisture content of the samples to 14%.

The following intercropping productivity indices were computed: 1. Relative Yield Total (R). In notation, this parameter can be expressed as:

Rc = Yci/Yc and Ri = Yic/Yi Where Yci = Yield of cane with intercrop

Yc = Yield of cane alone Yic = Yield of intercrop with cane Yi = Yield of intercrop alone

2. Land Equivalence Ratio (LER). This parameter provides measure to the total productivity of the land. It indicates the magnitude of advantage/disadvantage of growing crops together. In notation, LER = Rc + Ri

3. Area Time Equivalence Ratio (ATER). Proposed by Hiebsch5, this para- meter is analogous to LER except that time is involved. In the present connection, if Tc is the time the land is occupied by cane and Ti is the time the land is occupied by intercrop then - ATER = Rc/Tc + Ri/Ti

Farm budgets were prepared for each production alternative and the following profitability indicators were computed: (a) Net Return Above Direct Cost; (b) Return to Labour Cost; (c) Return to Material Cost; (d) Benefit Cost Ratio.

RESULTS AND DISCUSSIONS

Table Ia and Ib show the LER and ATER for total dry matter and economic yield, respectively.

In terms of dry matter, all of the intercropping systems, either legume or non- legume, showed advantage over monoculture (LER > 1). The advantage of inter- cropping was in the range of 7% (SC + cassava) to 84% (SC + soybean). Based on economic yield however, intercropping cassava and sweet potato with sugarcane did not show any advantage or benefit (LER < 1). Intercropping corn with sugarcane gave an LER compa~able to those of the legumes. In general, the legumes exhibited higher LER than the non-legumes. This was due to the better sugar yields obtained with legume intercrops compared to pure culture. Between the two intercropping

u F

TABLE la. Land Equivalency Ratio (LER), and Area Time Equivalency Ratio (ATER) in two intercropping schemes. o

Dry matter yield (tlha). 0

DRY MATTER YIELD CROP I u

l NTERCROPPING SCHEME DURATION Rc Ri LER ATER Suaarcane ln tercro~s Pure Months

1.5 Even Furrow Spacing

1 Sugarcanelcorn 38.5 8.0 13.1 3.0 -95 .61 1.56 3.78 2 SugarcanelCassava 14.2 15.2 21.1 7.5 .35 .72 1.07 1.19 3 Sugarcanelsweet Potato 32.7 4.9 7.4 4.0 .80 .67 1.47 2.67 4 SugarcanelMungbean 42.0 2.1 2.6 2.3 1.03 .80 1.83 5.28 5 Sugarcanelsoybean 45.9 1.7 2.9 3.0 1.13 .58 1.71 4.35 6 Sugarcanelpeanut 39.4 1 .O 3.9 3.3. .97 .25 1.22 3.19 7 Pure culture sugarcane 40.6 10

Double Row Scheme

1 Sugarcanelcorn 27.1 9.3 13.1 3.0 .67 .71 1.38 2.94 2 SugarcanelCassava 17.4 14.5 21.1 7.5 .43 .69 1.12 1.26 3 SugarcanelSweet Potato 28.7 4.7 7.4 4.0 .71 .63 1.34 2.41 4 SugarcanelMungbean 34.8 2.3 &6 2.3 .86 .89 1.75 4.65 5 Sugarcanelsoybean 38.0 2.6 2.9 3.0 .94 .90 1.84 4.04 6 Sugarcanelpeanut 28.1 2.2 3.9 3.3 .70 .56 1.26 2.69 7 Pure Culture sugarcane 40.26 10

w w

C

0 0

TABLE Ib. Land Equivalency Ratio (LER) and Area Time Equivalency Ratio (ATER) i n two intercropping schemes. Economic Yield.

ECONOMIC YIELD (KGIHA) CROP INTERCROPPING SCHEME DURATION Rc Ri LER ATER

SC (Kglha) lntercrop Pure Months

1.5 Even Furrow Spacing

1 Sugarcanelcorn 101 28 241 7 3575 3.0 .85 .68 1.53 3.51 2 SugarcanelCassava 4446 17060 28500 7.5 .37 .69 0.97 1.09

- - <

3 Sugarcanelsweet Potato 8930 J;;;? 197 8499 4.0 .75 .14 0.89 2.02 4 SugarcanelMungbean 12612 404 1245 2.3 1.06 .32 1.37 4.93 5 Sugarcanelsoybean 14104 309 1311 3.0 1.18 .24 1.44 4.17 6 Sugarcanelpeanut 12125 45 1 1192 3.3 1.02 .38 1.42 3.47 7 Pure Culture Sugarcane 11 922 10.0

Double Row Scheme

1 Sugarcanelcorn 8083 3077 3575 3.0 .68 .86 1.54 3.13 2 SugarcanelCassava ' 4642 13350 28500 7.5 .39 .47 .85 0.99 3 Sugarcanelsweet Potato 7954 3044 8499 4.0 .67 .36 1.03 2.04 4 SugarcanelMungbean 10777 834 1245 2.3 .91 .67 1.59 4.63 5 Sugarcanelsoybean 11 2270 793 1311 3.0 1.03 .61 1.65 4.04 6 SugarcanelPeanut 9158 91 8 1192 3.3 .77 .77 1.54 3.57 7 Pure Culture Sugarcane 11876 10.0 + 8

0 z 0

3

TEODORO C. MENDOZA 101

schemes, the double row plant consistently exhibited higher LER than the 1.5 m even-furrow spacing. These results confirmed earlier findings that the double-row planting was optimum for sugarcane + legume intercropping (Mendoza6).

For sugarcane + corn, in the double row scheme the sugar yield fell substantially (32%) but the reduction in the corn yield was moderate (14%). In the evenly spaced plan the effects were opposite - slight loss in sugar, heavy loss in corn. This suggests that corn can be intercropped in either scheme, single row or double but the effects are different.

Evaluated in terms of economic yield, intercropping root crops (cassava and sweet potato) provided no economic advantage to the farmer. However, inter- cropping cassava or sweet potato did appear to have some positive benefits if assessed in terms of total dry matter production. Cassava leaves have high protein content and when blended with other feed materials may make a good ration for ruminants. Sweet potato vines increase the digestibility and intake of rations consisting of sugarcane tops and molasses-urea mix.

ATER provided analogous indications in assessing the land utilization efficiency of any intercropping system. ATER values ranged from 0.99 (sugarcane + cassava) to 4.63 (sugarcane + mungbean). The value 4.63 indicates that the land was used 4.63 times as effectively as when used for sugarcane alone. This value however is just a mathematical artifact because neither alone nor as an intercrop can mungbean be grown successively on a given piece of land. Annual legumes cannot be grown continuously in the same piece of land. Opina8 reported an increased incidence of disease in soybean-soybean cropping patterns.

When analyzed in terms of dry matter and economic yield, ATER values were consistently higher for the legumes. The shorter the maturity of the intercrop the higher is the ATER. This is simply because the time T for the intercrop appears in the formula as a divisor, hence the lower the value of T, the higher the value of ATER.

Figure 1 shows the adjusted yields, botanic, (BY) and economic, (EY), in kg/ha in the different intercropping schemes including their pure culture. Sugarcane/ soybean at S1.5 and pure culture at F2 (S1 .O) exhibited the highest BY (47 307; 47 280 kg/ha respectively). In terms of adjusted economic yield, pure culture cane at F3 (S1.O) gave the highest value (15 603 kg/ha).

When BY and adjusted EY were added together, still sugarcane pure culture at F3 (S1.5) exhibited the highest total adjusted yield (62 503 kg/ha). Sugarcane + soybean at S1.5 had yielded a close value of about 61 933 kg/ha. These results imply that improved culture characterized by more fertilizer together with adequate weeding remains as an avenue for increasing productivity.

While sugarcane showed to be the more efficient in terms of converting inputs into biomass, it was a poor partitioner of assimilates in that only a small percentage went to economic yield (sucrose); of the above-ground, dry biomass only 20% to 24% was sugar. The non-legume intercrops (corn, cassava, sweet potato) likewise exhibited low AEY/TAY ratios. After adjustment of the yield leveh of legumes to equal levels of carbohydrate and taking account of the ratio AEY/TAY, legumes appeared to be more efficient partitioners of assimilates under pure culture.

However, legumes were less efficient in partitioning assimilates in favour of grain yield when intercropped because they tended to be more vegetative. The limited assimilates due to decreased photosynthetic rates were selectively used for photo- synthetic tissues like leaves due to shorter leaf area duration or faster leaf turnover rate.

TABLE !I. Profitability indices of various crops grown as intercrop and as pure culture.

CroplCulture Net Return to Return to Benefit Cost Revenue Labor Material Ratio

A. SUGARCANE + INTERCROPS

Sugarcane + Corn sugarcane + Cassava

Sugarcane + S. Potato

Sugarcane + Mungbean

Sugarcane + Soybean

Sugarcane + Peanut

B. Sugarcane Pure (Fertilizer

Experiment)

I 151 05.05 2.35 8.92 1.85

F2 20676.1 1 2.67 7.88 1.99

F3 24714.73 2.85 6.64 2.27 F4 1861 8.62 2.65 , 7.12 1.85

P - pure, sugar yield alone M - mixture, aggregate of sugar + intercrops

Table I1 shows the economic efficiency indicators for the various crops planted as a monocrop and/or intercrop. Net revenue from sugar for sugarcane intercropped with non-legumes decreased considerably compared to the monocropped sugarcane in all levels of fertilization. This decrease in net revenue was due mainly to the decrease in sugar yield. However, the net revenue from sugar for sugarcane inter- cropped with legumes did not differ significantly from that of pure culture at an average level of fertilization (F2) but was higher at a low rate (F,). This can be attributed mainly to the supplementary effects of legumes on a non-legume such as sugarcane.

104 AGRONOMY

The aggregate income in the sugarcane + legume intercropping was higher at the average fertilization (F2) but not at the higher fertilization rate (F3). At F4, sugar yield declined hence, net revenue also went down.

Return to labour was high when crops were grown in association, particularly for the legumes and also corn. This was because labour cost (land preparation plus weeding) was spread between the two crops. Because of the yield decline in the sugarcane + root crops, return to labour was low.

Return to material costs varied with polyculture. It was higher in the compatible crop combination (sugarcane + legume, sugarcane + corn) planted in adequate spatial arrangement (double row scheme for sugarcane + legumes and single row planting for corn) and lower in the non-compatible crop combinations (sugarcane

100

SHADED AREA INDICATES YIELDIREVENUE REDUCTION

50

1 F, F, F, F, SXKARCANE SUGARCANE SUGARCANE

150-75-200 350-75-400 + SUGARCANE + I SUGARCANE + 1 SUGARCANE

75-75-150 250-75-300 CORN + SW POTATO SOYBEAN + CASSAVA MUNG PEANUT

FIGURE 2. Sugar yield and net revenue in the fertilizer trial and computed total sugar yield and net revenue in the intercropping experimental express- ed as percent of yieldlrevenue in the F, (150-75-200) fertilizer treatment.

Note: For sugarcanelintercrop, total PSlHa = sugar yield + SEY of intercrop and any point in the curve represented the suitable spacing for the particular intercrop.

SEY = Yield of intercrop x Unit Price

Unit Price of Sugar

TEODORO C. MENDOZA 105

+ root crops). For sugarcane pure culture, there was a diminishing return from increasing material inputs. Return to material cost was highest at the lowest fertili- zation rate (75-75-150).

Another profitability indicator used in this study was the benefit cost ratio (BCR). BCR was higher in the compatible intercrops but not in crop mixtures with negative agronomic interactions (rootcrops + sugarcane). For sugarcane with inter- crops, the highest BCR was recorded for sugarcane + mungbean and lowest for the root crops. With sugar yield alone as the basis, the highest BCR was obtained for sugarcane + peanut (BCR = 2.35) and the lowest for sugarcane + cassava (BCR = 1.07).

In the sugarcane pure culture, BCR was highest at F,. This was because gross revenue increased in proportion to yield. The increase in production cost was offset by larger net revenue.

Figure 2 shows the sugar yield and net revenue in the fertilizer trial and the aggregated yield/net revenue in the intercropping experiment expressed as a percent of yield/revenue obtained in F,.

Increased fertilizer up to F3 level resulted in about 40% cash advantage above the average rate F,, but increasing in further (F4) actually reduced the yield and the revenue declined relative to F,. Intercropping corn, mungbean, soybean, and peanut provided cash advantages of about lo%, 40%, 20% and 5%, respectively. No cash advantages were derived from cassava and sweet potato as intercrops and from fertilizer treatment at the low level represented by F1.

SUMMARY AND CONCLUSION

Sugarcane intercropping generally resulted in higher land productivity parti- cularly under low to average input application. This was very evident in the sugarcane + soybean combination where the aggregate biomass yield at fertilizer level F2 was about the same as that of the above average level of fertilizer, F3.

In view of the high cost in the use of cash, sugarcane + legume mix was regarded to be the most productive and profitable production strategy. Highest aggregate yield (yield from sugarcane + sugar equivalent yield of the intercrop and net revenue) was derived in this intercrop combination.

Since labour and material costs (hired services, land preparation, weeding) were spread over two crops, return to labour and material cost, and finally benefit cost ratio (BCR) were higher in the compatible intercrop combinations.

The results obtained in both experiments indicated two recommendation domains. The first is a situation where a farmer has limited cash to purchase inputs, generally lower sugar productivity index, a family-operated farm, and on large sugarcane plantations. In this case, accrued benefits due to intercropping corn and legumes can be significant.

The other recommendation domain is a situation where a farmer has the cash to procure inputs, is technically equipped to manage and correctly apply the purchased inputs (and supply is not limiting), labour is a constraint, and the farmer is reluctant to learn the culture of other crops. Improved crop husbandry practices (adequate cultivation/weeding plus above adequate fertilizer input application) remain parts of productive and profitable cropping strategies for sugarlands.

REFERENCES

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3. Gomez, A.A. (1978). Multiple cropping: An answer to food production problems in the Philippines. Paper presented during the 9th Ann. Scientific Meeting of CSSP. May 11-13, 1978. Sarabia Mano, Iloilo City.

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6. Mendoza, T.C. (1979). Optimum spatial arrangement in sugarcane legume intercropping. M.S. Thesis. UPLB, Laguna, Philippines. 161 p.

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8. Opina, O.S. (1978). Consequences of intensive and sequential cropping on Schlerotium rolfsii and other pathogens associated with field legumes and sorghum. Ph.D. Thesis UPLB, 149 p.

9. Pening de Vries, F.W.T. (1974). The cost of maintenance process in plant cells. Ann, Bot. 39:77-92.

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11. Rosario, E.L. (1976). Towards maximization of sugar yield. Monograph presented by the author at U.P. College of Agriculture, College, Laguna, 14 p.

12. Syarifuddin, AS. , Effendi, S., Ismail, I.C., Mcintosh, J.L. (1974). Performance of corn, peanut, mungbean and soybean in monoculture and intercrop combinations of corn and legumes in dry season. Contr., Centr. Res. Inst. Agric. Bogor No. 12.

13. Tatangco, M.A. (1976). Fertilizer response of sugarcane under varying environment and management practices. M.S. Thesis UPLB Grad. Sch. Laguna, Phil. 176 p.