Household survey was carried out by soil testing formulated fertilization project from 2006 to 2009 in Qin-Ba mountain area of southern Shaanxi. The object was to evaluate current situation of fertilizer application and problems of nutrients input by households on rapeseed in this region. Data was collected from 2 576 households in11 counties. Results showed that in this area, the average yield of rapeseed was 2 355kg/hm^2 over 60.68% households. The rates of total N, P2O5 and K2O were 179, 80 and 54kg/hm^2 respectively. Among them, the chemical fertilizer rates were 145, 62 and 34kg/hm^2 respectively. Yield had significant correlation with chemical fertilizers. Diminishing return was found in each fertilizer input. According to yield level classification, households with rational chemical fertilizer （of N, P2O5 and K2O） rates were 38.55%, 27.60% and 25.89% respectively, while households with excessive application were 15.22%, 26.24% and 10.33% respectively, and households with insufficient application were 46.23%, 46.16% and 63.78% respectively. The survey showed that, if the chemical fertilizer was supplied at a rational level, the yield would increase 56.1 thousand tons. Using boron fertilizer would increase 101kg/hm^2 in yield. Moreover, households using organic and boron fertilizer were only 45.26% and 41.73% respectively, which could further increased. The problems of fertilizer input in this region were irrational nitrogen and phosphate inputs, as well as insufficient potassium, boron fertilizer and organic manure input. It was recommended to balance the nitrogen and phosphate application, increase potassium and boron fertilizers, increase organic manure inputs, and increase top dressing fertilizers, especially potassium.
Chinese Journal of Oil Crop Sciences
Qin - Ba mountain area of southern Shaanxi