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Interpretive Summaries:
2007 - Balanced Fertilization and Fertilizer Use Efficiency in Vegetables
2006 - Balanced Fertilization and Environmental Effects on Vegetable Soil
2005 - Balanced Fertilization and Environmental Effect on Fujian Vegetable Soils
Balanced Fertilization and Fertilizer Use Efficiency in Vegetables, 2007
Fertilizer consumption reached 400 million metric tons (M t) in Fujian Province in 2006. It has the highest fertilization rate per unit of arable land compared to other provinces in China, and this is largely due to its 600,000 ha planted to vegetables. Farmers typically over-fertilize their vegetable soils and this has become an important agricultural pollution source. The Soil and Fertilizer Institute of Fujian established this research in 2005. The main goal is to describe macronutrient absorption in vegetables, N and P desorption in vegetable soils, and the environmental effect of nutrient application in vegetables.
Amaranth fresh weight under an “optimum” (OPT) treatment was 240 g/pot or 164, 51, and 117 g higher than the treatments omitting N, P, and K, respectively. Use efficiency of N, P, and K in this pot study was 57%, 29%, and 86%, respectively. In the field, use efficiency of N, P, and K applied to edible amaranth was 28%, 6%, and 87%, respectively. This example of particularly low P use efficiency may be a result of higher available soil P, while low soil K availability may be the reason for the relatively high K use efficiency. Use efficiency of OPT N, P, and K fertilization in winter Chinese cabbage were 69%, 32%, and 78%, respectively. In early rice, use efficiency for N, P, and K fertilization was 43%, 20%, and 43%, respectively. Use efficiency of K applied on lettuce was 57%.
Experiments using edible amaranth, water convolvulus, and flowering Chinese cabbage determined nonlinear relationships between nitrate-N (NO3--N), total P, and K concentration in leached soil water and high application rates of N, P, and K fertilizers. However, these relationships were linear under mid to low rates of fertilization. The relationship between fertilizer loss and nutrient concentration in leached water was significant, positive, and linear.
Three balanced fertilization (BF) field demonstration plots for rice and green soybean were conducted in Yong’an City and Longhai City, respectively. Average early rice yield in the BF plot was 6,864 kg/ha, or 360 kg/ha more than farmer practice and 724 kg/ha more than the zero K plot. Green soybean yield under BF was 9,401 kg/ha or 851 kg/ha more than the farmer practice and 576 kg/ha more than the zero K plot. Balanced fertilization on rice increased net income by US$79/ha over common practice, while on green soybean BF increased net income by US$38/ha over common practice. Fujian-08
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