Abstract

This study evaluates the influence of phosphorus (P) fertilization (without and with added P fertilizer) and soil moisture (stress and no-stress) on efficacy, fate, and transformation of soil applied micronutrients such as copper (Cu), zinc (Zn), and Cu + Zn in a wheat and pea cropping sequence. Wheat was grown as first crop under controlled environment conditions in which micronutrient fertilizer treatments were applied, whereas pea was grown as following crop with recommended macronutrient fertilizers to understand the residual effects of micronutrient fertilization. The high-P fertilizer application and no-stress moisture condition produced the highest grain and straw yield of wheat. Without P fertilization, there were significant negative effects of a combined application of Cu and Zn on wheat yield in a Dark Gray Chernozem. Yield of the following pea crop did not show response to residual Cu and Zn. Micronutrient fertilization increased the Cu and Zn concentration in wheat and pea grain and straw and resulted in increased after-harvest availability and supply in soils. Apart from the increased concentration in labile fraction, a considerable amount of added Cu and Zn was occluded with organic matter and oxyhydroxide species, respectively. Molecular speciation analyses revealed that carbonate associated was the dominant form of Cu and Zn in the soils. Additional Cu species such as Cu-acetate and methoxide, and Zn species including Zn-sorbed montmorillonite species were identified. Insoluble Cu-phosphate and Zn-phosphate complexes were not identified by speciation analyses and do not appear to be a significant factor controlling Cu and Zn availability in these soils.

摘要

本研究评估磷 (P) 施肥（不加和加磷肥）和土壤水分（胁迫和非胁迫）对土壤施用的微量元素如铜 (Cu)、锌 (Zn) 的功效、命运和转化的影响。 )，以及小麦和豌豆种植序列中的 Cu + Zn。小麦在受控环境条件下作为第一茬作物种植，其中施用微量营养素肥料处理，而豌豆作为后续作物种植，采用推荐的常量营养素肥料，以了解微量营养素施肥的残留影响。施高磷肥和无胁迫水分条件使小麦的籽粒和秸秆产量最高。在不施磷的情况下，在深灰色黑钙土中，铜和锌的联合施用对小麦产量有显着的负面影响。以下豌豆作物的产量对残留的铜和锌没有反应。微量元素施肥增加了小麦、豌豆籽粒和秸秆中铜和锌的浓度，导致收获后土壤的有效性和供应增加。除了不稳定部分的浓度增加外，大量添加的 Cu 和 Zn 分别被有机物和羟基氧化物物质吸留。分子形态分析表明，伴生碳酸盐是土壤中 Cu 和 Zn 的主要形式。还鉴定了其他 Cu 种类，例如醋酸铜和甲醇盐，以及 Zn 种类，包括吸附锌的蒙脱石种类。形态分析未发现不溶性铜-磷酸盐和锌-磷酸盐复合物，它们似乎不是控制这些土壤中铜和锌有效性的重要因素。