Comparison of potential potassium leaching associated with organic and inorganic potassium sources in different arable soils in China

• Published in: Pedosphere Vol. 32; no. 2; pp. 330 - 338
• Main Authors: LU, Dianjun, DONG, Yanhong, CHEN, Xiaoqin, WANG, Huoyan, ZHOU, Jianmin
• Format: Journal Article
• Language: English
• Published: Beijing Elsevier Ltd 01.04.2022; Elsevier Science Ltd; University of Chinese Academy of Sciences,Beijing 100049(China)%Soil and Fertilizer Station of Shandong Province,Jinan 250100(China); State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008(China)
• Subjects: Agrochemicals; Arable land; arable soils; China; Corn; crop straw; Fertilizers; Fixation; K fixation; K source; K-bearing mineral; Leaching; Mineral fertilizers; Minerals; Mobility; Organic matter; Oryza sativa; Potassium; Potassium chloride; rain; rain intensity; Rainfall; Rainfall intensity; Rice; Rice straw; Sandy soils; Soil fertility; soil type; Straw; Zea mays; China; soil type; K-bearing mineral; crop straw; K fixation; K source
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/S1002-0160(21)60077-2

Potassium (K) leaching is detrimental to the maintenance of sustainable arable soil K fertility, especially in low-K fixation soils. It is not known whether the application of inorganic fertilizers with lower K mobility or crop straw can reduce potential K leaching in low-K fixation arable soils. The potential K leaching of 14 representative arable soils with different K fixation capacities in China was evaluated with or without the addition of K under two rainfall intensities (90 and 225 mm), and then potential K leaching was assessed in relation to five K sources (KCl, K2SO2, KH2PO2, maize (Zea mays L.) straw, and rice (Oryza sativa L.) straw). Without K addition, K leaching mainly occurred in sandy soils at 90 mm of rainfall and in soils with greater organic matter at 225 mm of rainfall. With K addition, the leaching percentage of exogenous K ranged from 0.6% to 11.6% at 90 mm of rainfall and 1.2% to 21.2% at 225 mm of rainfall. The greatest K leaching occurred in soils with fewer K-bearing minerals and lower pH at both rainfall intensities. In most cases, KH2PO2, which has lower K mobility, markedly reduced K leaching in both high- and low-K leaching soils at the two rainfall intensities. Maize and rice straw reduced K leaching only in soils with high K leaching, regardless of rainfall amount, whereas more K was leached in soils with lower K leaching at high rainfall intensity. In conclusion, KH2PO2 and straw should be preferred for reducing K leaching in low-K fixation arable soils.