Title: Leaf Nutrient Resorption in Lucerne Decreases with Relief of Relative Soil Nutrient Limitation under Phosphorus and Potassium Fertilization with Irrigation

Authors: Mei Yang, Jiaoyun Lu, Minguo Liu, Yixiao Lu, Huimin Yang*

Journal: Scientific Reports（综合性期刊3区, IF2020=3.998）

Doi: 10.1038/s41598-020-65484-1

Abstract: Leaf nutrient resorption is an important mechanism in adapting to adverse environments. However, few studies examine how nutrient resorption responds to phosphorus (P) and potassium (K) fertilization or to a shift in nutrient limitation due to water supply and fertilization. On the Loess Plateau of China, we treated lucerne (Medicago sativa L.) with P, K, or combined P and K fertilizer and three levels of water supply. The resorption efficiency of leaf P (PRE) and K (KRE) decreased with increasing water supply, whereas that of N (NRE) was unaffected. The water supply regulated the effects of P and K fertilization on resorption efficiency. With low water, P fertilization reduced NRE and significantly increased KRE. Potassium fertilization did not affect KRE and NRE, whereas PRE was significantly affected. NRE increased with increasing green leaf N:K ratio, whereas KRE and PRE decreased with increasing K:P and N:P ratios, respectively. Water supply significantly increased soil nutrient availability interactively with P or K fertilization, leading to a shift in relative nutrient limitation, which was essential in regulating nutrient resorption. Thus, lucerne growth was not limited by K but by P or by P and N, which P fertilization and water supply ameliorated.

文章链接：https://doi.org/10.1038/s41598-020-65484-1