Evaluation of the situation of fertilization in apple fields in Shaanxi province

In order to understand the current situation of fertilization and nutrients resource input problems of farmers in apple fields in Shaanxi province, and to put forward countermeasures to solve the problems, we used household survey data, which collected from the project of soil testing and formulated fertilization from 2005 to 2009, to evaluate the situation. There were totally 21 counties and 7141 households. The results show that the ratios of households who used organic manure in the Loess plateau area of northern Shaanxi, the Weibei tablelands and the Guanzhong irrigated area are 99.96%, 24.52% and 20.37% respectively, and the averaged ratio in the whole province is 50.15%. The application rates of chemical fertilizer NPK from the Loess plateau area of northern Shaanxi to the Guanzhong irrigated area have increasing trends, and the amounts of nitrogen fertilizer are from 490 to 619 kg/ha, the amounts of phosphate fertilizer are from 318 to 447 kg/ha and the amounts of potassium fertilizer are from 73 to 382 kg/ha. On the whole, the chemical fertilizer NPK rates and organic manure rates have very significant correlations with the yield in all regions, and the fertilizer and organic manure inputs show diminishing return trends. Compared with the levels of fertilizer rates, in the Loess plateau area of northern Shaanxi, the Weibei tablelands and the Guanzhong irrigated area, for chemical N application, 18%, 17% and 12% are rational respectively and the average of the whole province is 17%, and 67%, 74% and 78% are excessive and the average of the whole province is 72%; for chemical P2O5 application, 12%, 27% and 15% are rational and the average of the whole province is 20%, and 42%, 52% and 65% are excessive and the average of the whole province is 50%; for chemical K2O application, 11%, 12% and 14% are rational and the average of the whole province is 12%, and 84%, 48% and 15% are insufficient and the average of the whole province is 56%. The current situation of household fertilization in apple fields in Shaanxi province is that nitrogen fertilizer inputs are excessive, phosphate fertilizer inputs are both excessive and insufficient, and potassium fertilizer and organic manure inputs are both insufficient. Therefore, increasing organic manure inputs, significantly reducing nitrogen fertilizer inputs and reasonable application of phosphate fertilizer should be concerned for households in Shaanxi province. In addition, increasing potassium fertilizer inputs in the Loess plateau area of northern Shaanxi and the Weibei tablelands.