Controlled-release potassium blended fertilizer mitigates greenhouse gas emissions in paddy fields

• Published in: Nutrient cycling in agroecosystems 2023-12, Vol.127 (3), p.317-331
• Main Authors: Ahmad, Sajjad, Gao, Shen, Li, Quanxin, Nadeem, Muhammad Yousaf, Tao, Weike, Yang, Fei, Ding, Yanfeng, Liu, Zhenghui, Li, Ganghua
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Chlorine compounds; Climate change; Controlled release; Crop yield; Dry matter; Emissions; Emissions control; Fertilizers; Global warming; Grain; Greenhouse effect; Greenhouse gases; Life Sciences; Methane; Nitrates; Nitrous oxide; Original Article; Phosphorus; Potassium; Potassium chloride; Potassium nitrate; Resins; Rice; Rice fields
• ISSN: 1385-1314; 1573-0867
• DOI: 10.1007/s10705-023-10309-6

Fertilizer management is commonly suggested as an option to mitigate greenhouse gas emissions in rice fields. Controlled-release fertilizers are the best choice among various fertilizers for reducing greenhouse gas emissions in rice fields without impacting crop output. Therefore, in the current study, the novel controlled-release potassium blended fertilizers (CRKBF) at the levels CRK1: 180 kg K ha −1 , resin potassium nitrate, 112.5 kg P ha −1 resin phosphorus fertilizers from superphosphate, CRK2: 90 kg K ha −1 , 50% reduced resin potassium chloride, 112.5 kg P ha −1 resin phosphorus fertilizers from superphosphate, CRK3: 90 kg K ha −1 , 50% reduced resin potassium nitrate, 112.5 kg P ha −1 resin phosphorus fertilizers from superphosphate were used in comparison to CK0: where no fertilizer was applied, CK1: 180 kg K ha −1 , K locally recommended fertilizers from potassium nitrate and CK2: P and K blended fertilizers, 112.5 kg P ha −1 , phosphorus from superphosphate and 180 kg K ha −1 from potassium chloride, to find the best possible way to reduce greenhouse gas emissions without affecting the yield of rice. During a 2-yr period, CRKBF amendments significantly increased rice yield and its related components, i.e. panicles m −2 , grains panicle −1 , 1000-grain weight, seed setting rate, and dry matter accumulation. Among CRKBF, CRK1 treatments recorded higher grain yields of 11.4 t ha −1 and 10.7 t ha −1 , followed by CRK2 (11.1 t ha −1 and 10.5 t ha −1 ) and CRK3 (10.7 t ha −1 and 10.3 t ha −1 ), respectively. Considering greenhouse gas emissions, CRKBF treatments significantly reduced methane emissions. CRK1 mitigated methane emissions by 33%, CRK2 reduced methane emissions by 25%, and CRK3 decreased methane emissions by 21%. In terms of nitrous oxide emissions, CRK1 and CRK3 treatments increased nitrous oxide emissions, while CRK2 treatment reduced nitrous oxide emissions. CRK1 enhanced nitrous oxide emissions by 56% followed by CRK3 which increased nitrous oxide emissions by 30%, whereas CRK2 reduced nitrous oxide emissions by 21%. Among CRKBF, CRK2 has the potential to mitigate area-scale global warming potential (area-scale GWP) by 21% and yield-scale global warming potential (yield-scale GWP) by 30%. The results of the study indicate that amendment of CRKBF having 50% K from potassium chloride (CRK2) to paddy fields is an effective approach to reduce greenhouse gas emissions from paddy fields without affecting the rice yield and can be a promisin