Effects of controlled‐release potassium fertilizer on available potassium, photosynthetic performance, and yield of cotton

Abstract

Potassium (K) is one of the major mineral elements required for normal growth of cotton. However, understanding the effect of controlled‐release K fertilizer on leaf photosynthesis and K use efficiency (KUE) of cotton is currently limited. A two‐year pot experiment was consecutively conducted in 2014 and 2015 with three kinds of K fertilizer including K2SO4, KCl, and polymer‐coated KCl (CRK), each at four application rates (0.00, 0.86, 1.73, and 2.59 g K plant−1, respectively). For each type of K fertilizer, the yield and K uptake of cotton increased but the KUE decreased with higher K fertilizer application. The release characteristics of K from CRK corresponded well to the K requirements during cotton growth. Plant‐available soil K, as well as leaf SPAD values, net photosynthetic rate (Pn), maximal photochemical efficiency (Fv/Fm), and effective quantum yield of photosystem II (ΦPSII) in CRK treatments were increased after full bloom stage compared to conventional K fertilizers under the same potassium application rate. Consequently, the CRK treatments significantly increased lint cotton yields by 8.1–32.7% and 3.7–20.8%, while the KUE increased by 15.5–54.8% and 14.5–45.4% compared to KCl and K2SO4 treatments, respectively. The results indicate that the application of CRK is intensively recommended to replace conventional potassium fertilizers for gaining greater yields and higher KUE of cotton.

Effect of Potassium Sources and Soil Amendments With Silicate Dissolving Bacteria on Availability of Potassium in Clayey Soil Cultivated With Wheat Plants

“…The highest biological yield, 1000-grain weight and protein content of wheat were found in pots treated with K-sulphate combined with FYM+S in the presences of SDB, while the lowest ones were obtained with untreated soils in absence of soil amendments and SDB. These results agree with those obtained by Abdallah et al (2013) and Tian et al (2017).…”

Effects of potassium application on soil ecological resistance to Verticillium wilt of cotton (Gossypium hirsutum L.)

“…It is worth mentioning that the number of fungi in the rhizosphere soil was positively correlated with bacteria and V. dahliae. available K, which was easily absorbed and utilized by plants (Lean and Watson 1985;Tian et al 2017). Potassium in the rhizosphere soil also affected the content of cotton root exudates.…”

Combined effects of straw-derived biochar and bio-based polymer-coated urea on nitrogen use efficiency and cotton yield

“…To achieve an identical BPCU (bio-based polymer-coated urea) with a release rate synchronized with cotton growth, the BPCU (40% N) used in this study was coated with liquefied cotton straw [16,17] and epoxy resin [18,19]. The total weight of the LCS (liquefied cotton straw) and epoxy resin coating accounted for 7.5% wt (6.0% of the LCS and 1.5% of the epoxy resin) of the urea fertilizer.…”