Effects Of Regional Climate Change And Regulation Of Water And Nitrogen In Orchard On Apple Production In Shaanxi Province

This paper provides a theoretical basis and application reference for the scientific and rational agricultural production and the efficient allocation of water resources in the areas of Shaanxi Province,which is a clear understanding of the temporal and spatial characteristics of climate change and its impacts in main apple producing areas of Shaanxi,this is of great significance to the healty of Shaanxi apple industry healthy and it's sustainable development.This paper is divided into two parts: regional analysis and fixed point experiment.Based on the Penman-Monteith formula,the water demand of the main growth period of apple from April to October was calculated based on the meteorological data of 19 meteorological stations in 1961~2013 in the main apple producing areas and surrounding areas in Shaanxi Province.The climate productivity potential was calculated by Thornthwaite Memorial model.Using time series method,spatial interpolation and correlation analysis to study the variation trend,spatial distribution characteristics and influencing factors of water demand,irrigation requurement index and climate productivity potential in Shaanxi apple main producing areas.The effects of drip irrigation and nitrogen fertilizer on apple were studied by real-time monitoring of soil water dynamics and meteorological factors,as well as apple growth,yield and quality indexes,based on the soil water and daily meteorological data of orchards.The main conclusions are as follows:(1)The monthly mean temperature,monthly mean maximum temperature and monthly mean minimum temperature of the main growth period of apple(April ~ October)in the study area were increasing,and the monthly mean wind speed,monthly mean relative humidity,cumulative sunshine duration and monthly effective precipitation decreased.The warm index,annual biological temperature,effective temperature,mildness and photosynthetically active radiation of the study area showed an increasing trend,and the cold index,the warm index,the annual difference and the comprehensive coefficient of water and heat were declining.The single climate factors of main growth period of apple and the annual comprehensive factors of the study area indicated that the climate had a warm and dry trend.(2)In 1961 ~ 2013,the average water requirement of apple growth in the study area was 463 ~ 699 mm,the irrigation requirement index was 0.06 ~ 0.52,and the climatic production potential was 7372~11012 kg?hm-2?a-1.Most of the sites in the study area had the lowest water requirement,irrigation requirement index and net irrigation water requirement in 2010 ~ 2013,the highest water demand in 1970~1997,and irrigation requirement index and the highest net irrigation water requirement in 1990~1999,in main apple growth period.The climatic production potential in 1990~1991 was the lowest overall,compared with the highest in 2010~2013.(3)The spatial distribution of the study area showed that the spatial distribution characteristics of irrigation requirement index and the water requirement of the main apple growth period are obvious and consistent,all of which are increasing from southwest to northeast.The spatial distribution of climate production potential is opposite,it decreasing from southwest to northeast in erery age.The demand for irrigation requirement index and crop water requirement of the majority of the site showed a decreasing trend,but the irrigation requirement index and net irrigation water requirement showed an increasing trend in most of the sites.Overall,the study area of climate production potential decreased significantly in the most sites.(4)The main influencing factors of the total water requirement during the main apple growth period are the cumulative sunshine hours,the monthly mean temperature,the monthly maximum mean temperature and the monthly mean wind speed.The main influencing factors of the climatic production potential are relative humidity,sunshine hours and precipitation.There is a negative correlation between the water requirement of the apple growth period and the climatic productivity potential in the study area.(5)Under the suitable conditions of nitrogen fertilizer,the new shoots increased first and then decreased with the increasing of irrigation amount.However,if the topdressing amount of nitrogen fertilizer was too high,it would decrease with the increasing of irrigation amount.In summer,the appropriate topdressing nitrogen fertilizer would not make fruit trees grow,but if the topdressing of nitrogen fertilizer improper,it would inhibit the growth of new shoots.No matter what kind of nitrogen,the increase of irrigation would help increase the fruit diameter,and then increase the yield;the amount of topdressing nitrogen fertilizer would help the fruit growth,but the high nitrogen amount would make the fruit growth limited.(6)Irrigation during apple growth could significantly increase the yield of apple trees,and the yield would increase with the increasing of irrigation amount.Appropriate irrigation could improve the intrinsic quality of apple,but too much irrigation would not only reduce the efficiency of irrigation water,but lead to apple's inherent quality decline.The appropriate application of nitrogen fertilizer in summer was beneficial to the formation of yield,the improvement of irrigation water use efficiency and the improvement of fruit quality.However,the application of nitrogen fertilizer improperly would be counterproductive,especially the high nitrogen application would not only lead to the yield and irrigation water use efficiency decline,but also didn't conducive to the development of apple's inherent quality.The results showed that the yield and intrinsic quality of apple were the best at 75% ?f irrigation level and 0.57 kg / tree nitrogen level,in orchard positioning experiment based on soil water content.Orchard orientation experiment based on daily meteorological data showed under 80 % I(I means apple's net irrigation)irrigation level and 0.46 kg /tree nitrogen level,the yield could be slightly reduced in the case of apple's inherent quality to achieve the best.(7)Apple fruit canopy different parts of the fruit quality indicators there are differences.Soluble sugar,soluble solids,hardness and VC were significantly larger than that of the other.The average height of the crown was 15.03%,7.59%,37.18% and 9.88% higher than that of the inside,respectively.The titratable acid and sugar and acid ratio were basically the same.(8)The apple bagging effect were different under the irrigation and nitrogen treatments.,The soluble sugar increased first and then decreased with the increasing of light and temperature under the irrigation treatment,and the titratable acid increased with the increasing of light and temperature.Soluble solids,sugar and acid ratio,color L value and color b value decreased with the increasing of light and temperature,VC increased with the increasing of light and temperature,the hardness increased with the increasing of light and temperature,the color a value increased with the increasing of light and temperature.In the case of nitrogen storage,the soluble sugar showed no significant difference,the titratable acid increased with the increase of light and temperature,and the soluble solid and color b value decreased with the increase of light and temperature.VC,hardness and color a value increased with the increase of light and temperature,the ratio of sugar to acid and color L were increased with the increase of light and temperature.In terms of the intrinsic quality of the fruit,the combined quality of the normal bagging under irrigation and nitrogen storage is the best,and the overall quality of the bag has been poor.In the case of the external quality of the fruit,the color of the peel is the most red,but the fruit is rough;the peel color under the normal bagging is red and the fruit is smooth.Fruit of the bag under the fruit color bright yellow and white,fruit surface is the most smoothly.