Experimental Study On Irrigation Quantity In Arid Area Of Central Ningxia

In view of the problems of water shortage,extensive irrigation methods,and unclear key parameters for irrigation in the arid region of central Ningxia,based on soil moisture control at different growth stages,the key parameters for irrigated soil irrigation were developed in the central arid region of Ningxia,and the random area was used.The method was used to study the characteristics of the tap water and the characteristics of soil moisture under the drip irrigation conditions in the central arid region of Ningxia,and the effect of different water on the growth index,quality index,photosynthetic physiological characteristics and yield index of the alfalfa.The water control indexes in different growth stages were determined.The key parameters for the quantity of irrigation were calculated,and the appropriate amount of irrigation system was proposed for the arid area in central Ningxia.The conclusions of the study can provide comprehensive analysis and judgments for the decision-making of irrigation quantity in the region,and provide technical and theoretical support for the scientific planting of earthworms in the central region of Ningxia.It is of great significance to the development of the aphid industry in the central arid region of Ningxia and the increase of farmers' income.The main findings of this article are as follows:(1)The soil moisture content between 20?60cm is the largest in the soil layer and it is the main soil layer for the growth of earthworms.The soil moisture content is between 3.4%and 12.7%at 20?40cm and the soil is between 40?60cm.The water content ranged from 4.8%to 12.9%.Excavation of taro strains in the experimental area showed that the main roots were distributed in 30?40 cm,and some of the roots could penetrate deep into the 60?80 cm soil layer.(2)The photosynthetically active radiation exhibits a "doublepeak curve" variation pattern.The first peak occurs at 10:00 and the minimum peak value occurs at 12:00.The second peak occurs at 14:00 and ends at 16:OO.The 00 point reached another minimum value,and there was a slight upward trend until 18:00.The leaf sto matal conductance showed a "convex parabola" change rule.The peak appeared at 10:00 and 12:00;the transp iration rate showed two variations.One is a "singleconvex parabola type" and the other is a "doublepeak conv ex parabola type";the photosynthetic rate as a whole exhibits a "bimodal convex parabola" variation pattern.(3)According to the analysis and calculation,the water requirement for the whole growth period is from 290.85?336.01mm.The maximum water use efficiency and water production efficiency are treated as S5 wi th a value of 30.93 yuan/m3;The maximum values of plant height,crown width,shoot stem diameter,and sho ot length growth were all treated with S5.The highest values of the quality indicators for beryllium,polysacch arides,proteins,and amino acids also appeared in the treatment of S5;the highest dried fruit production was tr eated with S5.At 72.46 kg/667m2,50g seeds with S5 treatment had the smallest number of 249 seeds.The per formance of S5 in the evaluation of various parameter indexes is optimal.(4)The characteristics of soil moisture,growth,photosynthetic characteristics,quality and yield were comprehensively analyzed during the whole growth period.The parameters of the S5 treatment performed optimally.The optimal irrigation system was:the total growth period was divided into 6 During the irrigation period,the irrigation period was 25 M3/667m2 in the germinating stage(spring water)and 30 m3/667m2 in the dormant period(winter water).The other periods were divided into 4 irrigation periods:50%?f(?f is the field water holding capacity)during the spring shoot growth stage.In the vegetative growth stage and flowering stage,irrigation(early flowering stage,fruit ripening stage)65%?f,irrigation during fruit period(late fruit ripening stage,early autumn fruit stage)65%?f,irrigation of 55%?f in autumn fruit period.When the soil moisture content in each growth period is lower than the lower limit of each water control period,water should be promptly filled,and the upper limit of irrigation is 95%?f.