Effects of Households’ Fertilization Knowledge and Technologies on Over-Fertilization: A Case Study of Grape Growers in Shaanxi, China

Over-fertilization has caused serious environmental problems and high agricultural production costs at the household level in China. This study attempts to analyze the effects of grape growers’ fertilization knowledge and technologies on their over-fertilization behavior. Using survey data collected from 235 grape growers planting a particular grape (the “Hutai No. 8” grape) in Shaanxi, the marginal productivity of the chemical fertilizer (CF) as well as the effect of fertilizing knowledge and technologies on households’ over-fertilization behavior were examined, using the loss control production function and examining a two-part model, respectively. The results show that the average marginal productivity of the CF is 0.46 and that more than 75% of the participants were overusing CFs, with the probability and intensity of over-fertilization being lower when households have richer knowledge on how to determine the accurate fertilization time and match fertilizers with nutrient needs. The identification of nutrient deficiency symptoms has no significant effect on the over-fertilization behavior of households. In addition, the adoption of water and fertilizer integration technology (WFIT) can reduce both the probability and intensity of over-fertilization, while the adoption of the soil testing and formulated fertilization technique (STFFT) helps to reduce only the intensity of over-fertilization by households, but does not have a significant impact on the probability of over-fertilization. Therefore, policies aimed at reducing over-fertilization may focus on increasing households’ fertilization knowledge and adopting advanced technologies on fertilizer management.