Modeling the effect of fertilizers on cotton yields and cotton fiber quality on saline soils in so uthern Kazakhstan

Abstract

   Yntymak st.,26, Kazakhstan Cotton in Kazakhstan is one of the strategically important crops and is cultivated in the extreme south of the republic in the Turkestan region, in the northernmost cotton-growing zone on the globe. The aridity of the climate, the shortage of irrigation water and the growing threat of the risk of increasing saline lands in cotton plantations, on the one hand, and the insufficient and unjustified use of minerals, on the other, are the main limiting factors in cotton production. On the industrial plantations of the peasant farm "Sabyr", v. Atakent, Maktaaral district, Turkestan region, field experiments were carried out on serozems of slightly and moderately salinity in 2022. In experiments on two salinity backgrounds, 9 identical treatments of fertilizers with different doses and ratios of nitrogen, phosphorus and potassium were studied. During the phases of budding, flowering and fruit formation of cotton, biometric studies and selection of plant samples were carried out to study photosynthetic and yield indicators depending on fertilizers on 2 salinity backgrounds. The effect and interaction of fertilizers and the amount of salts in the soil on the formation of leaves in various phases of cotton development isquite accurately described (R2 = 0,957-0,972) by regression equations. At the same time, the effect of single action of nitrogen and potassium fertilizers was negative, and that of phosphorus fertilizers was positive. During the growing season, double combinations of all the studied factors, with the exception of nitrogen and potassium, had a negative effect on the dynamics of accumulation of cotton plant biomass. The gross cotton yield is 86% determined by the complex total influence of nitrogen, phosphorus and potassium fertilizers and the degree of soil salinity. At the same time, the unilateral effect of nitrogen and potassium fertilizers and soil salinity on cotton yield was negative, and that of phosphorus fertilizer was positive. There is a high correlation between potassium nutrition and fiber quality indicators (r = 0,38-0,62). Changes in fiber quality indicators generally had a strong relationship with the amount of salts in the topsoil (r = 0,51-0,61).