Study On The Interaction Effect Of Precipitation Year And Fertilization Amount On Wheat Field

Drought and water in the Loess Plateau is a typical rain-fed agricultural area and an important wheat producing area in China.The interannual precipitation in this area is unevenly distributed,the soil organic matter content is low,the nutrient supply is unbalanced,and the yield fluctuates greatly between years.At present,fertilization techniques are mostly based on experience,and there is a lack of long-term positioning experiment quantitative research,thus increasing wheat yield and its stability.reducing fertilizer waste,improving fertilizer utilization,and protecting the ecological environment are crucial to China's food production safety.In order to study the effects of different fertilization treatments on yield in wheat production in different regions of the region,a long-term fertilization experiment on wheat was carried out in Shilipu,Changwu County,Shaanxi Province.The main research contents were in dry years,normal years and wet years.Three different precipitation-type fertilizer effect equations were used to study the effects of different nitrogen and phosphorus application rates on the three factors of wheat yield and yield under different precipitation years.The maximum yield of wheat and the amount of economic fertilizer were calculated to guide the production of farmers.practice.Research indicates:1.When the application of phosphate fertilizer 180 kg hm^-2,the yield of wheat decreased slightly,and the annual yield reduction reached 0.44%;the yield of wheat with single application of nitrogen increased slightly,and when the nitrogen application reached180 kg hm^-2.The annual yield increase is only 0.5%;when nitrogen and phosphorus are combined,the wheat yield is significantly increased.When the amount of nitrogen and phosphorus is N 180 kg hm^-2 and P?P₂O₅?180 kg hm^-2,the annual yield of abundant water is1.16 times of the normal year and 1.42 times of the dry year.With the increase of nitrogen and phosphorus dosage,the law of yield increase is:wet year>normal year>dry year.The variation coefficient of yield and the sustainability index of wheat with different nitrogen and phosphorus application rates were different.The coefficient of variation?CV?of long-term non-fertilization was small,the coefficient of variation of single-application phosphorus fertilizer was the largest,and the coefficient of variation of single-application nitrogen fertilizer was relatively small.The coefficient of variation at the time of application was the smallest;the sustainability index?SYI?without fertilization was lower,the SYI of the single application of phosphate fertilizer was the lowest,and the SYI value of single application of N fertilizer was relatively large,and the SYI of nitrogen and phosphorus application was the largest.Only the application of phosphate fertilizer,the number of spikes of wheat in different precipitation years did not differ much,the normal year was slightly higher;the application of nitrogen and phosphorus combined,the number of spikes per year of abundance was significantly higher than that of normal years and dry years.The grain number per spike of wheat increased the most in wet water,and the variation range of grain number per ear in rich water was 11.87%-26.5%,which was the most stable among the three types.The 1000-grain weight of normal years is higher than that of wet water year and dry year under the same fertilization conditions.The coefficient of variation of 1000-grain weight of wheat in the year of rich water[the coefficient of variation CV should be a percentage]is the smallest,and the fluctuation range is 5.40-9.20,which is the most stable.2.Fixed phosphate fertilizer increased nitrogen fertilizer application rate and fixed nitrogen fertilizer increased phosphorus fertilizer application rate was different from that of precipitation type wheat,but the yield eventually reached a certain maximum value and no longer increased.The highest yield was expressed as dry year<normal year<wet year.The effect of different precipitation type of lower gradient nitrogen and hosphorus on the growth of production cycle is different.The decline rate is the fastest in dry year,and the decline rate in normal year and abundant water is relatively moderate.In the dry year,the nitrogen fertilizer was in the range of 137.65-148.24 kg hm^-2 and the phosphate fertilizer was 137.65-148.24 kg hm^-2.The increase of wheat yield was weakened compared with before.The increase of nitrogen and phosphorus fertilizer had no obvious effect on the yield increase of wheat.Normal year As in wet year,the growth rate of nitrogen in the range of 158.82-169.41 kg hm^-2 and phosphorus application rate of 158.82-169.41 kg hm^-2 began to increase negatively.At this time,the maximum yield of wheat has been reached.3.The amount of nitrogen and phosphorus required for the highest yield of ifferent precipitation type wheat is different.The nitrogen application rate is 144.4 kg hm^-2,the phosphorus application rate is 155.5 kg hm^-2,and the highest yield of wheat is 3530.4 kg hm^-2.The amount of 172.2 kg hm^-2,phosphorus application rate is 164.9 kg hm^-2,the highest yield of wheat is 4229.8 kg hm^-2;the annual nitrogen application rate is 175.8 kg hm^-2 and the phosphorus application rate is 162.9 kg hm^-2.The highest yield is 4896.7 kg hm^-2.The economic fertilization amount is different for different precipitation years.The conomic nitrogen application rate is 135.7 kg hm^-2 in the dry year,and the economic phosphorus application rate is 143.8 kg hm^-2.The normal annual economic nitrogen application rate is 161.7 kg hm^-2,and the economic phosphorus application rate is 161.7 kg hm^-2.It is 151.4 kg hm^-2;the economic nitrogen application rate in Fengshui is 167.1 kg hm^-2,and the economic application is 153.3 kg hm^-2.The economic nitrogen and phosphorus fertilizer application rates are 6%-8%lower than the highest nitrogen and phosphorus application rates.