![Page 1: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/1.jpg)
Nutrient management for organic vegetable
production in NC
http://compost.tamu.edu/demos/palopinto/compost.jpg
Part I
![Page 2: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/2.jpg)
Nitrogen Phosphorus Potassium
Average rates of N, P2O5 and K2O applied to vegetable crops in the US
Why are these rates so high ?
http://www.ers.usda.gov/publications/sb969/sb969c.pdf
(lbs/acre)
![Page 3: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/3.jpg)
Most growers believe that high rates of nutrients are needed to produce
high yields of high quality vegetables
![Page 4: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/4.jpg)
Jalapeno pepper production in Fresno County, California
Total cost of production: $4392Total fertilizer costs: $170
Fertilizer costs = 4% of total costs
![Page 5: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/5.jpg)
N K Ca Mg P S
macronutrients micronutrientsair & water
Soil
~ 16 elements have been identified as essential for the growth of all plants
C O H Cl Fe Mn Zn B Cu Mo
Na
Co Si
V NiNeeded by
some plants
![Page 6: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/6.jpg)
Micronutrients are critical components of enzymes
![Page 7: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/7.jpg)
Soil solidscontain nutrients
minerals
organic matter
![Page 8: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/8.jpg)
exchangeableions
Soil soup
Humus
Clay
-
-
--
-
-
-
-
--
Na+
Ca+2
H+
K+
Ca+2
Mg+2
K+
H20H20
H20
H20
H20H20
H20H20
H20
H20
H20
H20
H20
H20
H20
H20
H20
Soil water contains nutrients
![Page 9: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/9.jpg)
What’s in the soil soup ??
Adapted from Brady and Weil (2002)
Ca+2
NO3-
Ca+2
K+
K+
Mg+2Ca+2
Mg+2
Ca+2
Mg+2
Ca+2
NO3-
NO3-
SO4-2
NO3-
H2PO4-
DOM
DOM
DOMCu+3
Fe+3
Zn+2
![Page 10: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/10.jpg)
Which forms of nutrients are available to plants ?
solution
exchangeable
“active” OM
passive “OM”
weatherable minerals
![Page 11: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/11.jpg)
Re-seasoning the soup
Modified from Havlin et al. (1999)
Poorly bufferedHighly buffe
red
![Page 12: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/12.jpg)
……
Nutrient availability
Cro
p
yield
DeficiencySymptoms
![Page 13: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/13.jpg)
http://www.extension.umn.edu/distribution/horticulture/components/M1190fig1.htm
![Page 14: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/14.jpg)
![Page 15: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/15.jpg)
Understanding nutrient uptake
Transpirationalstream
Ro
ot g
row
th
H20
H20
Root exudatesactivate soil
microbes
![Page 16: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/16.jpg)
?
Acute root
disease
Feed the soil vs. Feed the crop ?
Chronic root malfunction
Both strategies are important !
Healthy roots need available nutrients !
Unhealthy roots use nutrients inefficiently…
![Page 17: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/17.jpg)
The acid infertility complex
![Page 18: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/18.jpg)
Nutrient availability
varies with pH
![Page 19: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/19.jpg)
Understanding aluminum toxicity
Toxic forms of Al are
bioavailableat low pHs
Aluminum toxicity is minimal above pH 5.5
http://www2.ctahr.hawaii.edu/tpss/research_extension/rxsoil/alroot.gif
![Page 20: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/20.jpg)
Exchangeable
Al+3
Brady and Weil (2002)
100%
50%
0%
75%
25%
Percentage of m
aximum
cation exchange capacity
![Page 21: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/21.jpg)
Avoid over-liming !!
http://www.fftc.agnet.org/library/image/bc51002p7.html
Micronutrientdeficienciesfrequently occur when
naturally acidsoils are
over-limed
![Page 22: Nutrient management for organic vegetable production in NC Part I](https://reader030.vdocuments.site/reader030/viewer/2022032722/56649cdd5503460f949a85cd/html5/thumbnails/22.jpg)
http://hubcap.clemson.edu/~blpprt/acid2-chart1.gif