Effect Of The Drip Irrigation Wetting Pattern On The Cotton Growth And Yield

Drip irrigation is the partial irrigation, the crop yield is influenced by the soil wetting pattern under drip irrigation since crop root system is under the influence, so the relation between the soil wetting pattern and crop yield is necessary to detemine the drip soil wetted percentage, but there are quite few research results in view of this question in the domestic and foreign countries. Based on the planting cotton in barrels, the width of soil wetting pattern was controlled by drip discharge, and the distribution of soil moisture of different width soil wetting pattern, correspondingly the cotton growing state as well as the yield and the cotton water consumption law of different width soil wetting pattern, and so on, by observing, analyzing and studying these problems. There are 5 treatments of drip discharge on the planting cotton in barrels, 0.5L/h, 1L/h, 1.5L/h, 2L/h, 2.5L/h, which are separately displayed treatmentⅠ,Ⅱ,Ⅲ,Ⅳ,Ⅴto obtain different width soil wetting pattern, observing 5 treatments have impact on growing status and yield on the cotton 5 growth stages, namely seedling stage, bud stage, flower stage, boll stage, blooming of boll stage. soil moisture content is measured by neutron moisture content detector and MP moisture content detector, stem height and leaf area are measured by the ruler on the cotton every growth stage, the boll weight, dry matter weight overground part and yield are measured by the electronic balance. the results are obtained as follow.(1) Drip discharge has a great impact on the shape, size of soil wetting pattern and the distribution of soil moisture, which has larger impact on the width of moisture than the depth, soil wetting pattern is the broad-shallow pattern under the large drip discharge and the narrow-depth pattern under the small drip discharge, on the horizontal direction, the distribution of soil moisture content decreased gradually from the center outward, however, water ratio has a greater reduction under the small drip discharge, and shallow soil moisture content under the large drip discharge is larger than relative shallow soil moisture content under the small drip discharge; on the depth direction, with the drip discharge increasing, moisture content increased under the water drop below and shallow soil, deep soil moisture content lowers.(2) Cotton root growth, growth and yield closely relate with the size of drop irrigation soil wetting pattern. Different soil wetting patterns have different root distribution, the structure of cotton root zone consists with the spatial distribution of soil wetting pattern.By analyzing, comparing to cotton growth traits and analyzing of variance to cotton yield, drop irrigation soil wetting pattern has impact on cotton growth traits and yield, drop irrigation soil wetting patterns are better under the narrow-depth pattern and broad-shallow pattern, drop irrigation soil wetting patterns are not good in the middle, so it is very appropriate for drop irrigation cotton soil wetting patterns under the 2.5L/h or 0.5L/h drip discharge.(3) Under drop irrigation, cotton water consumption depth basically is less than 60cm, and cotton water accepting layer is in the upper layer mainly, cotton roots water uptake is the easier part first; Water consumption of cotton in the whole growth period has the law of both sides small and broad in the middle, namely seedling stage and term of opening bolls are smaller, bud stage and blooming, boll period are bigger, the largest intensity of water consumption presents to blooming period, which is close to 10mm/d. Soil wetting pattern had no obvious effect on total water rate of cotton in the whole growth period, but according to promting its root growth and ensuring its yield, we need to control soil wetting area as wide and shallow at the seeding and budding stage, and control it as narrow and deep at the flowering and bell stage.Among every soil wetting pattern treatment, soil moisture movement raises with soil wetting pattern increasing, water consumption and seed cotton yield are both the largest under the wide soil wetting pattern, the total water consumption and yield is relationship of cubic parabolic, to a certain extent, the higher that water consumption is, the higher that yield is.