Low soil fertility impairs cotton yield in the early years of no-tillage over degraded pasture

Abstract

No-till is one of the main techniques for soil conservation and the mitigation of negative climate impacts. The objective of this study was to evaluate soil fertility, nutrition, cotton yield, and the fiber quality of cotton under different soil tillage systems. The study was carried out in the field in the 2017/2018 and 2018/2019 crop seasons. The experimental design was a complete randomized block with five replications. No-till (NT) and conventional tillage (CT) farming were used in the 2017/2018 and 2018/2019 crop seasons. NT resulted in higher soil bulk density (0-35 cm) than CT. When compared to NT, the availability of calcium, magnesium, potassium, phosphorous, cation exchange capacity, base saturation, zinc, and pH were 120, 90, 43, 135, 49, 110, 41, and 8% higher in areas with CT, respectively. Boron content was 14% higher with NT (0-20 cm) than CT. Leaf concentrations of nitrogen, Ca, and Mg were higher with CT in both seasons, and B was higher with NT. However, in the second season (2018/2019), leaf concentrations of P, K, and sulfur were higher with NT than CT. When compared to NT, fiber yields were 75% and 32% higher with CT in the 2017/2018 and 2018/2019 seasons, respectively; this corresponded to a difference of 757 and 420 kg ha-1 of fiber. However, no effects on fiber quality parameters were observed. NT limits the availability of most nutrients in soil in the early years of cotton cultivation; this reduces plant nutrition and fiber yield but has no effect on quality.