Potassium management over 60 crops: A long‐term study on an Oxisol under no‐till

Abstract

Potassium (K) is a typical yield‐limiting nutrient for soybeans [Glycine max (L.) Merr.] in humid tropical regions. The effect of fertilization on K balance over 32 yr of continuous cropping was investigated in a highly weathered Rhodic Hapludox under no‐till. The nutrient balance was calculated based on the amounts of K added via fertilization and on the amounts removed by the crops. Potassium rates interfered with yields over time and modified the final balance of K in the system. Depending on K rates, the balance tended to be positive or negative, and the range of K rates evaluated allowed us to establish conditions of either continuous K depletion, resulting from K removals by harvests, or the accumulation in soil under high rates. In this range, indicators of the efficiency of K fertilizer also varied and made it clear that K fertilizer is not the only source of K for plants.

The challenge of alleviating potassium limitation in major cropping systems of Southeast Asia

“…Unfortunately, prediction of yield responses to K fertilizer has remained elusive, and commonly available soil tests are not su ciently robust to predict adequate K supply 11,18 . Furthermore, there is a long-term cumulative effect of K fertilization on crop yields, which makes it more di cult to identify marginal K limitation 19,20 .…”

Potassium buffering capacity and corrective potassium fertilizer recommendations in soils from Southern Brazil

“…Based on the results of this study, considering different KBC values and CEC pH7.0 , it could result in more assertive recommendations. Thus, it is possible to rationalize the use of K fertilizers, reducing the production cost and the potential for contamination, but with adequate plant nutrition (Vieira et al, 2016;Firmano et al, 2019Firmano et al, , 2020.…”

“…Potassium (K) is an essential nutrient for plants and highly demanded by agricultural species (Firmano et al, 2020). Together with nitrogen (N), it is the nutrient absorbed in greater quantities by plants (Filippi et al, 2021), and when in excess in the soil, plants can use it beyond their need for luxury consumption (Kang et al, 2014;Fornari et al, 2020).…”

“…In addition, inadequate fertilization management where outputs are higher than inputs can lead to K content depletion, negatively impacting crop yields (Firmano et al, 2019;Gatiboni et al, 2020). Thus, for optimal K management, it is important to supply K at adequate levels to meet crop demand (Firmano et al, 2020) and decrease the K transfer potential, especially, by runoff (Ceretta et al, 2010;Wang et al, 2019;Wolka et al, 2021).…”