Quantifying potassium requirement and removal across crop species
Walter D. Carciochi, Achim Dobermann, Nicolás Cafaro La Menza, Sylvie M. Brouder, C. R. Donough, D. Jo Heuschele, Thomas Oberthür, Patricio Sandaña, Bello Muhammad Shehu, J. C. R. Pereira, Rogério Peres Soratto, Jeffrey J. Volenec, Ruli Wandri, Yajing Wang, Su Su Win, Ping He, Patricio Grassini
Abstract
Potassium (K) management is crucial for addressing global yield gaps in agricultural systems. To determine K uptake requirements, K internal efficiency (KIE), and K removal for several crops at different yield targets while assessing the factors driving variation. We compiled a comprehensive database to determine K requirement, KIE, and K removal for various yield potentials. We assessed intra- and inter-species variations in KIE and compared the K-related parameters across 14 crop species. The K uptake requirements increased with crop yield, with an average two-fold smaller K requirement (22 versus 41 kg K) and 4-fold smaller K removal (3.8 versus 15 kg K) per ton of harvested organ in cereals than soybean. Variations in KIE within crops were related to K harvest index (KHI) in maize and wheat and K concentration in harvested product (KCHP) in soybean. Variation in KCHP across species was related to protein and moisture content. The KIE ranked as follows: cassava and sugarcane (87) > cereals, potatoes, and alfalfa (41−58) > banana and oil-rich crops (10–30 kg kg⁻¹ K). Net K removal increased with higher yield, KHI, and crop residue removal. The K uptake requirement increases with yields, while KIE decreases as yields approach potential yield. Variation in KIE among species derives from differences in KCHP and KHI. Thus, effective K management must consider yield levels, crop choice, and residue management. We provided a foundation for quantifying K requirements and removals across crop species and target yields, offering essential insights for sustainable K management in agroecosystems. • Poor potassium (K) management contributes to global yield gaps. • We compared K requirements and removal for 14 crop species. • The K requirement and removal were two- and four-fold smaller in cereals than soybean. • Highest K internal efficiency in sugarcane and cassava and lowest in oilseeds and banana. • Our findings can serve as a basis to increase yield via better K management.