Effect Of Drip Irrigation Arrangement On Water-salt Transport Law Of Mechanically Harvested Cotton

Xinjiang is an important cotton producing area in my country,but there are problems such as time and cost of manual picking during the harvest period.Object: in order to solve this problem,the corps began to introduce mechanical cotton picking process.Methods: the machine-plucked cotton planting is a brand-new model,and the existing water and salt transport laws and irrigation systems also lack scientific relevance.For the above problems,this paper carried out field experiments,mainly explored the effects of two drip irrigation arrangements and three different irrigation limits on the soil water and salt in the cotton field,and combined with the corresponding characteristics of cotton growth and development,yield and other indicators,proposed suitable for Xinjiang mechanical harvesting Water-saving and salt-reducing drip irrigation arrangement and high-quality and high-yield water control strategy under cotton planting mode.Results:(1)By analyzing the effect of different drip irrigation arrangements on the soil water and salt survival environment of mechanically harvested cotton fields.The soil moisture status is summarized as follows:the dynamic changes of soil moisture in cotton fields treated by different drip irrigation arrangements are basically the same over time.The water content in the early and late periods is low,and the soil water content in the middle period is high.The overall change trend of the soil moisture content in the longitudinal section of the whole growth period of different drip irrigation arrangements is basically the same,but there is a certain difference in the vertical water content corresponding to different horizontal positions.On the whole,the M1 model(one film and two tubes)has a low soil water content,and the cotton plants have a certain degree of water stress.The soil salinity status is organized as follows: the soil salinity content of each treatment has changed with time,but the overall change trend is basically the same,which is completely opposite to the dynamic change of the average soil moisture content.The content is low,and in the later period,the salt began to migrate to the superficial layer and accumulated.The distribution characteristics of the longitudinal profile show that the salinity content of the surface and deep soils is relatively high,and that of the shallow and middle soils is small.From the beginning of the bud period,the advantages of M2(one film and three tubes)treatment desalination effect began to increase,which can form an effective salt desalination area in the root growth area of cotton plants.(2)Under different drip irrigation arrangements,the total bioaccumulated dry weight of cotton showed a gradual increase and then a slight decrease.The indicators of M2 treatment,such as single boll weight,boll number per plant,seed cotton yield and irrigation water utilization efficiency,were significant Better than M1 processing.(3)By analyzing the effect of drip irrigation arrangement and water treatment on soil and water survival environment of mechanically harvested cotton field.The soil moisture status is summarized asfollows: Throughout the growth period,the changes in soil mass water content showed a regularity that the water content gradually increased and then decreased over time.In the middle and late stages of cotton growth,the difference in soil moisture content between treatments increased significantly.The W1M2 and W2M2 treatments can keep the machine harvested cotton at a higher water content during the flower and bell period.Among them,the drip irrigation arrangement(one film and three tubes)and water regulation of the W2M2(bud period: 60% irrigation limit,flower bell period: 70% irrigation Lower limit)The synergistic effect of treatment can make the crop at an appropriate soil moisture content.The soil salinity status is summarized as follows: under the treatments of orthogonal drip irrigation arrangement and water regulation,the salt washing efficiency of the whole growth period basically increases with the increase of irrigation quota,and the arrangement of M2 drip irrigation can be more than that of M1 Effectively make the roots of the crop growth stage appear light salt desalination range,W1M2,W2M2 treatment have achieved a desalination effect of more than 55%.(4)The plant height and stem thickness of cotton gradually increase with time,and the plant height and stem thickness have a positive correlation.In terms of dry matter accumulation,the interaction between different drip irrigation arrangements and water regulation is obvious.W2M2 had the highest single bell weight,seed cotton yield and irrigation water utilization efficiency.Compared with other treatments,W2M2 increased yield by 11.8%~37.3%,and IWUE increased by 13.7%~26.3%.Conclusion: comprehensive analysis shows that a suitable irrigation system and drip irrigation arrangement can simultaneously achieve water saving and production increase.In terms of drip irrigation layout,M2 has certain advantages in water distribution uniformity,root zone moisture content and desalination effect;in terms of water treatment,the comprehensive control effect of W2 water strategy is the best.It is concluded that the W2M2 test treatment(irrigation: 60% in the bud period,70% in the flower bell period;drip irrigation arrangement: one film and three tubes)reflects the more excellent interaction between water use and crop growth in the growth index of cotton plants Can effectively guarantee the output of cotton in the later period and meet the requirements of efficient water use.