Investigation and evaluation of household wheat fertilizer application in Shaanxi Province

【Objectives】 Clarify of farmers' nutrient input situation in winter wheat is the base for scientific suggestion in winter wheat nutrient resource managements in Shaanxi Province, which is the aim of this survey.【Methods】 A five-year consecutive investigation was carried out to define farmers nutrient input status in winter wheat production in two winter wheat production areas, Weibei and Guanzhong of Shaanxi Province.【Results】 The obtained results show that the wheat yields in Weibei are low and unstable because of rainfall distribution uneven from year to year, and the average yield of this area is 3473 kg/hm2, while the wheat yields in Guanzhong are high and stable with an average of 5882 kg/hm2 because of irrigation supplication. Only 29.7% of farmers apply reasonable amount of nitrogen fertilizer in Weibei area, while 20.2% is in high amount, 43.5% is the highest amounts, 4.6% is low and 2.0% is the lowest, and the average rate is N 197.6 kg/hm2. In Guanzhong area, only 17.5% of farmers apply reasonable amount of nitrogen fertilizer, while 20.3% is high, 37.5% is the highest, 14.2% is low and 10.5% is the lowest, and the average rate is N 199.2 kg/hm2. The average phosphate fertilizer that farmer applied is rational, but over-applied and inadequate applied coexist. Only 12.0% of farmers apply reasonable amount of phosphate fertilizer in Weibei area, while 41.5% is low, 10.7% is the lowest, 26.7% is high and 9.2% is the highest, and the average rate is P2O5 123.4 kg/hm2. In Guanzhong area, only 14.3% of farmers apply reasonable amount of phosphate fertilizer, while 27.2% is low, 13.8% is the lowest, 31.0% is high and 13.7% is the highest, and the average rate is P2O5 141.6 kg/hm2. Potassium fertilizer apply amount is K2O 32.9 kg/hm2 in Weibei, while K2O 37.3/hm2 in Guanzhong. More than 90% of farmers apply inadequate potassium fertilizer. The base fertilizer is the main nutrients for winter wheat, and the topdressing is supplementary. The average base fertilizer application amounts are N 189.9 and 185.4 kg/hm2 in Weibei and Guanzhong respectively which account for 96.1% and 93.1% of whole nitrogen nutrient input in the two areas. The topdressing application amounts are N 7.7 and 13.8 kg/hm2 in Weibei and Guanzhong respectively which only account for 3.9% and 6.9% of whole nitrogen nutrients input. Chemical fertilizers are the main nitrogen and phosphorus nutrients, while organic manure is supplementary. The average nitrogen amounts from organic manure are N 4.7 and 3.1 kg/hm2 in Weibei and Guanzhong respectively, only account for 2.4% and 1.6% of whole nitrogen nutrient inputs in the two areas, while the average P2O5 nutrients from organic manure are 2.4 and 1.7 kg/hm2 in Weibei and Guanzhong respectively, only account for 1.9% and 1.2%. The average nitrogen nutrients from chemical fertilizers are N 192.9 and 196.0 kg/hm2 in Weibei and Guanzhong respectively, and the average P2O5 are 120.8 and 139.9 kg/hm2 from chemical fertilizers respectively. The average PFP of N, P2O5 and K2O are 20.0, 33.3 and 83.5 kg/kg in Weibei area respectively, and 36.8, 53.9 and 131.8 kg/kg in Guanzhong area respectively. Urea and ammonium bicarbonate are the most favorite nitrogen fertilizer varieties applied for winter wheat which are selected by farmers in Weibei area, there are 55.7% of farmers selecting urea and 47.2% selecting ammonium bicarbonate in this area. But in Guanzhong area, the farmers' favorite nitrogen fertilizer is urea, 42.8% of farmers select urea for winter wheat. The calcium superphosphate is the most favorite phosphorus fertilizer for wheat in Weibei area, the selecting percentage is 50.2%. But in Guanzhong area, the favorite phosphorus fertilizer is diammonium phosphate with selecting percentage of 40.2%. Compound fertilizer application area has been increasing year by year, there are 30.8% and 40.2% of farmers applied it in Weibei and Guanzhong areas respectively. Organic manure is not often applied by farmers, and the application percentages of farmers keep decreasing in recent years. The percentage of farmers applying organic manure was 10.0% and 11.7% in Weibei and Guanzhong in 2008-2009, but it was decreased to only 0.8% and 0.8% in 2012-2013.【Conclusion】 In the whole province of Shaanxi, the nitrogen fertilizer amounts for winter wheat are much more than necessary; the phosphate fertilizer is averagely reasonable, but the excessive and insufficient coexist; the potassium fertilizer applications are not fully recognized, the organic manure inputs are seriously deficient. The topdressing of fertilizer should be supplementary for higher efficiency.