permaculture

["Lawrence F. London, Jr." <lflj@intrex.net>]

Journal of the Science of Food and Agriculture J Sci Food Agric 88:7–23 (2008)
Review: Effects of fertilization and other agronomic measures on nutritional 
quality of crops
Zhao-Hui Wang,1∗ Sheng-Xiu Li1 and Sukhdev Malhi2
1College of Resources and Environmental Science, Northwest Agriculture and 
Forestry University, Yangling, Shaanxi, PR China
2Agriculture and Agri-Food Canada, Research Farm, Melfort, Saskatchewan, 
Canada

Abstract: Crops, as the basic source of essential substances and nutrients, 
do not always contain sufficient
amounts of these essential nutrients to meet dietary requirements. In this 
review paper, we discussed the effects
of fertilization and other agronomic measures on the nutritional quality of 
cereal, oilseed and protein crops, tuber
plants and vegetables. Research indicates that application of N, P, K and S 
fertilizers generally increases crop
yield as well as nutritional quality. For example, fertilizer increased 
protein concentration in cereals and pulses,
oil concentration in oilseed crops, starch concentration in tubers, and 
concentration of essential amino acids and
vitamins in vegetables. However, excessive fertilizer application, especially 
N fertilizer, can result in undesirable
changes such as increases in nitrate, titratable acidity and acid to sugar 
ratio, while decreasing the concentration
of vitamin C, soluble sugar, soluble solids, and Mg and Ca in some crops. 
Other agronomic measures, such as
tillage and crop rotation, organic farming, soil moisture management, and 
crop breeding and genetic engineering
can also have a large effect on food crop quality, though the potential 
benefits of these measures for improving
crop quality has not been fully exploited. Research literature on this 
subject suggests that more information is
needed in order to achieve an increase in the concentration of essential 
microelements, prevent accumulation
of toxic levels of elements such as Cu, Mo, Zn, Ni, Se and nitrate, and other 
dangerous or toxic substances and
elements in crops.