Nitrogen, Phosphorus, and Potassium Resorption Responses of Alfalfa to Increasing Soil Water and P Availability in a Semi-Arid Environment

作者：Meng Kong, Jing Kang, Cheng-Long Han, Yan-Jie Gu, Kadambot H. M. Siddique, Feng‐Min Li · 发表于：Agronomy · 年份：2020 · DOI：10.3390/agronomy10020310 · 被引用次数：21 · 研究领域：Irrigation Practices and Water Management、Plant nutrient uptake and metabolism、Seedling growth and survival studies

In semi-arid areas, alfalfa (Medicago sativa L.) is widely grown, but its growth is often restricted due to limited rainfall and soil nutrients, particularly phosphorus (P). Nutrient resorption is an effective strategy for dealing with nutrient shortages. Alleviation of these limited resources using film mulch and P fertilization—which are common practices in semi-arid areas—can affect the internal recycling of such nutrients. Little is known about such effects in alfalfa and the relationship between resorption efficiency and forage yield. We conducted a two-year field experiment in the semi-arid Loess Plateau of China using film mulch and P fertilization to investigate the response to long-term increasing soil water and P availability on leaf nitrogen (N), P, and potassium (K) concentrations and nutrient resorption characteristics in alfalfa. In green leaves, mulching significantly increased P concentration by an average of 5.5% but it had no significant effect on N concentration over two years, and it decreased K concentration by 16.1% in 2017. P fertilization significantly increased N concentrations to a greater degree in 2018 (8.1%) than 2017 (1.6%). P fertilization also significantly increased P concentrations by an average of 34.1% over two years. In contrast, P fertilization significantly decreased K concentration in the mulched treatment by an average of 17.3% in 2017 and 21.8% in 2018, but it had no effect in the no-mulch treatment. In senescent leaves, mulching sign...