Effect Of Water And Fertilizer On Apple Growth And Evapotranspiration Estimation In Weibei Plateau

The development of apple economic forest in Weibei arid plateau is of great significance to the local economic development.Due to the long time of illumination and high evaporation intensity,the excessive consumption of water resources seriously restricts the further development of the local apple industry.Traditional irrigation mode makes the improving the quality of the apple production and bottlenecks,and serious waste of the resources of water,so the exploit apple economic forest transpiration water consumption,in order to promote high quality under the premise of optimal production sewage sludge utilization and develop effective reasonable fertigation system become the key step of apple planting,at the same time,the farmers’income,ecological improvement and economic development has positive significance.This test in the shaanxi province luochuan fruit trees experimental station in northwest agriculture and forestry university of science and technology field apple cucumber in experiment,further explore the Han Yuan apple water consumption,the influence of different sewage sludge treatment on the apple tree stem flow,and compared the effects under the condition of apple production,quality,and comprehensive economic benefits,to explore the optimal gave birth to improve utilization rate of water quality,fertilization strategy.The following conclusions are drawn:（1）During the growth period of apple trees,the daily value of evapotranspiration of reference crops varied in the range of 1.5～7.5mm,and the daily water consumption of apple trees increased first and then decreased.It is easy to make errors in the measurement data of stem-flow meter in extreme weather,but overall,the stem-flow method has a high accuracy in the calculation of apple tree evapotranspiration.During the growth period of apple trees,the soil evaporation coefficient Ke did not change significantly,while the basic crop coefficient Kcb continued to increase.After apples ripened,the leaves fell off and the increase gradually decreased.（2）the irrigation amount was consistent.With the increase of fertilizer application,the correlation between the daily stem flow of fruit trees and meteorological factors such as daily temperature,daily radiation and daily relative humidity gradually decreased.With the same fertilizer application amount,the correlation between daily radiation amount,average daily temperature and surface temperature and stem flow reached the highest value in medium water,and the correlation between relative humidity and daily stem flow increased with the increase of irrigation amount.The change of irrigation amount had no obvious effect on the relationship between wind speed and daily stem flow rate.In terms of the influence of water and fertilizer on stem flow rate,the sequence of stem flow rate is:medium water>high water>low water;Medium fertilizer>high fertilizer>low fertilizer,the coupling effect of water and fertilizer on the stem flow of fruit trees has a greater promoting effect than single nutrient level treatment and single water treatment.（3）with the increase of fertilizer application,apple yield showed a trend of ladder increase;There is a threshold value of the irrigation amount in the medium water.To a certain extent,increasing the amount of fertilizer applied can significantly increase the average fruit weight of apples,decrease the fruit hardness,increase the fruit longitude and longitude,and increase the edible rate.With the same amount of fertilizer applied,the higher the irrigation water,the greater the weight of single fruit.There is a threshold value of irrigation and fertilization on the quality improvement of apple.Beyond the threshold value,the effect of water and fertilizer on the quality is not significant,and even damages the quality.During the period of apple fruit growth,F2W2 treated fruit was more dominant in commercial fruit classification.F3W2 treatment(irrigation of 533 m³?hm^-2 and fertilization of 500 kg?hm^-2)is the best treatment to improve the utilization rate of water and fertilizer and obtain the maximum economic benefits on the premise of ensuring high quality and superior yield.