Effects Of Combined Application Of Nitrogen,Phosphate And Potassium Fertilizer And Single Basal Fertilization Of Controlled-released Nitrogen For Summer-sowing Millet

With the improvement of people's living standard,the demanding of millet in China was sustained increasing.However,the planting area of millet was decreased year by year due to the limited income caused by large labor consumption and low yield.In order to increase crop yield and fertilizer use efficiency of millet,the efficient fertilization technology was necessary established to reduce the cost of fertilizer and labor input.In this study,field test with"3414"fertilizer experiment and indoor analysis were employed from 2015-2016 to investigate the effects of different nitrogen,phosphorus and potassium ratio on grain yield,agronomic characters and nutrient uptake of“Jigu 16”.Meanwhile,non-fertilization?CK?treatment was designed as control,and the effects on growth,yield and nutrient utilization by the conventional fertilization?CF?,single application of sulphur coated urea?SNUr?,single application of resin coated urea?RNUr?,sulphur coated urea basal application+urea?SN+Ur?and resin coated urea basal application+urea?RN+Ur?treatments were also studied.This study was aimed to screen out the optimal nitrogen,phosphorus and potassium ratio based on the fertilization effect,promoting the popularization of controlled-release fertilizer.The main results were as follows:?1?The ratio of N,P and K behaved significant effect on the yield of millet.The yield of N1P2K2 was the highest,which reached to 3927.0 kg·hm^-2,and 68.8%higher than that of N0P0K0.Based on the regression equation of yield and fertilizer application amount,combined with the local farmers'fertilization habit,the optimum amount of fertilization could be comprehensively determined:the best nitrogen application rates was 130.4kg·hm^-2173.56 kg·hm^-2,the best phosphorus application rates was 83.5 kg·hm^-2103.8kg·hm^-2,and the best potassium application rates was 133.4 kg·hm^-2153.2 kg·hm^-2.?2?The reasonable ratio of N,P and K could significantly improve the agronomic characters of millet.The present study showed that higher correlation was performed between N,P,K and stem diameter.However,no significant effect was detected on the improvement of other agronomic characters.The chlorophyll SPAD value responded to nitrogen fertilizer greatly,and a reasonable amount of nitrogen fertilizer application and a rational ratio of nitrogen,phosphorus and potassium could increase the chlorophyll SPAD value by4.5%²0.1%;?3?Fertilization and fertilizer types had significant effects on N,P and K uptake in millet.Compared with CF treatment,the nitrogen content of millet grains decreased by 3.0%¹2.1%under high application amount of nitrogen.In the case of no phosphorus application or high application amount,the phosphorus accumulation in millet grains reduced by 2.1%¹2.2%.At the same time,in the case of no potassium application or high application amount,the potassium accumulation in millet grains reduced by 4.1%³3.5%.?4?Single basal fertilization with controlled-release nitrogen fertilizer could significantly increase grain yield.Under the same application rates of fertilizer,the yield of single basal fertilization with controlled-release nitrogen fertilizer treatments were 5.8⁶.5%higher than that of conventional fertilization treatment.Meanwhile,the apparent use efficiency of nitrogen fertilizer was increased by 10.6%¹9.9%,the agronomy use efficiency was increased by 54.7%⁵6.8%,the physiological use efficiency was increased by 11.3%¹3.1%,and the economic benefit was improved by 18.0%²0.5%in single basal fertilization treatments.