Study On Fertilization Effect And Fertilizer Recovery Efficiency Of Three Major Grain Crops In Shaanxi Province

Shaanxi Province is a major agricultural province in China.In 2000,the grain yield of Shaanxi province accounted for 2.4% of the whole country,and by 2015,it only 1.9%.The proportion of grain output of Shaanxi Province in the national grain yield gradually decreases.Therefore,it is crucial to keep the stability of grain yield for food security and economic development of Shaanxi Province.Now,there are many problems,such as the uneven fertilization of farmers,fertilizer utilization rate is not clear and so on.In order to study the relationship between the application of fertilizer and the yield of corn,rice and wheat,multi-point repeatless design experiment was used to analyze and evaluate the fertilizer utilization rate of three major grain crops in Shaanxi Province.It is expect that the results can provide a basis for improving the rational utilization of resources,the fertilizer utilization rate and the fertilizer application technology in Shaanxi Province.The results show that:1.The fertilizer recovery efficiency of N,P and K were 36.57%,20.72% and 42.29% in wheat planting system;27.32%,17.81% and 40.36% in corn;39.85%,27.21% and 31.66% in rice,respectively.So,they all showed the trend of K>N>P in three kinds of grain crops.Compared with the research results of our research group in 2011-2012,in this study,except for the decrease of fertilizer recovery efficiency of rice potassium fertilizer,the fertilizer recovery efficiency of wheat and Corn Nitrogen,phosphorus,potassium fertilizer and rice nitrogen,phosphorus fertilizer increased to varying degrees.The fertilizer recovery efficiency of phosphate fertilizer increased the most in wheat and rice,which were 183.6% and 192.6% respectively.2.The agronomic efficiency reflects the yield increasing effect of fertilizer.The agronomic efficiency of N,P and K fertilizer in wheat was 9.78kg/kg,13.28kg/kg and 14.94kg/kg,respectively;5.89kg/kg,10.08kg/kg and 11.83kg/kg in maize;14.44kg/kg,18.28kg/kg and 17.42kg/kg in rice.There have same rule for the agronomic efficiency in wheat and maize,that is,K>P>N,while in rice,P>K>N.3.The physiological efficiency reflects the efficiency of fertilizer nutrients absorbed by the crops to transform into yield in the plant.The physiological efficiency of N,P and K fertilizer in wheat was 26.92kg/kg,54.77kg/kg and 39.12kg/kg,respectively;21.59kg/kg,82.72kg/kg and 37.99kg/kg in corn;38.46kg/kg,90.83kg/kg and 57.45kg/kg in rice.They all showed the trend of P>K>N.It can be seen that physiological efficiency is related to the transformation of fertilizer nutrients in plants.4.Partial factor productivity is an important index to evaluate the relationship between fertilizer application and yield.In this study,the partial factor productivity of wheat was 38.99 kg/kg,74.63 kg/kg and 122.20 kg/kg,32.23 kg/kg,100.79 kg/kg and 135.23 kg/kg in corn,63.64 kg/kg,148.03 kg/kg and 134 kg/kg in rice.In conclusion,it is K>P>N in wheat and maize,while rice is P>K>N.In addition,the partial factor productivity of the three elements also showed that the grain yield was larger after applying potassium fertilizer under the current soil conditions.5.The fertilizer contribution rate reflects the degree of crop dependence on fertilizer,while the soil contribution rate reflects the degree of crop dependence on soil nutrient,which is the opposite.In wheat,the fertilizer contribution rate of N,P and K was 25.6%,17.94% and 12.24% respectively,and the soil contribution rate was 74.4%,82.06% and 87.76%.In maize,the fertilizer contribution rate were 19.43%,11.87% and 10.94% respectively,while the soil contribution rate were 80.57%,88.23% and 89.25%.Therefore,the soil contribution rate showed a trend of K>P>N in wheat and maize.It shows that the yield formation of wheat and maize is highly dependent on potassium in the soil and less nitrogen.In rice system,the fertilizer contribution rate of N,P,Kwere 23%,13.69%,14.75% and 77%;and the soil contribution rate were 86.31% and 85.25% respectively.The soil contribution rate of P is the largest.This may be related to the long-term submergence of paddy soil,resulting in the release of phosphorus in the soil.6.The yield increase rate is the ratio of the yield increase to the yield in the deficient area.In wheat planting system,the highest yield increase rateis nitrogen(37.15%),followed by phosphorus(23.15%),and the lowest is potassium(14.51%);the corn is 26.53%,14.90% and 14.09%;the rice is 30.98%,18.21% and 21.64% respectively.The yield increase rate of nitrogen fertilizer is the largest among the three food crops.Therefore,nitrogen fertilizer plays a decisive role in plant growth and yield formation,which is also the reason why farmers prefer to apply nitrogen fertilizer.