This present investigation took place on a continuing long‐term fertilizer experiment, initiated in 1972 at the experimental farm of the College of Agriculture CSK HPKV, Palampur, aimed at studying nutrient dynamics of micronutrients, especially Zn, after continuous use of chemical fertilizers and amendments over the previous 36 years in an acid Alfisol under a maize–wheat system. Treatments investigated were as follows: T₁: Control; 100% N; 100% NP; 100% NPK (optimal application ‐ 120:26:33(maize)/25(wheat)); 100% NPK + FYM (10 t ha⁻¹ to the maize crop); T₆: 100% NPK + lime (900 kg ha⁻¹); T₇: 100% NPK + Zn (25 kg ha⁻¹ as ZnSO₄); T₈: 100% NPK + Hand weeding; T₉: 100% NPK (‐S); T₁₀: 150% NPK (super‐optimal application); and T₁₁: 50% NPK (sub‐optimal application). Different forms of zinc in soil were determined through a sequential extraction method. Results revealed that previous applications of high‐analysis fertilizers and amendments caused a marked depletion in the pools of Zn as compared to buffer plots. All pools of Zn as well as crop productivity and Zn uptake were noticeably greater in farmyard manure (FYM)‐amended plots compared with plots not receiving fertilizer. The residual fraction was the dominant form but organically bound and exchangeable forms were found to play major role in nutrient supply, crop productivity and nutrient uptake. Correlation and regression analysis studies showed that organic forms constituted the most important pool contributing towards variation in yield and uptake by maize and wheat crops. Exchangeable and organically bound forms contributed significantly towards the availability of DTPA‐extractable Zn in soil.

中文翻译：

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长期使用化肥和玉米-小麦种植顺序修正的锌的动态

本次调查是根据一项持续的长期肥料试验进行的，该试验始于1972年，位于农业大学CSK HPKV实验室，帕兰普尔（Palmpur），其目的是研究持续使用化学肥料和改良剂后微量营养素（尤其是锌）的营养动力学。在过去的36年中，在玉米-小麦系统中使用酸性Alfisol。研究的治疗方法如下：T ₁：对照；T ₁：对照。100％氮; 100％NP; 100％NPK（最佳应用-120：26：33（玉米）/ 25（小麦））; 100％NPK + FYM（玉米作物10吨公顷^-1）；T ₆：100％NPK +石灰（900 kg ha ^-1）；T ₇：100％NPK + Zn（25kg ha ^-1的ZnSO ₄）；T ₈：100％NPK +人工除草 T ₉：100％NPK（‐S）；T ₁₀：150％NPK（超级最佳应用）；和T ₁₁：50％NPK（次优应用）。通过顺序提取方法确定了土壤中锌的不同形式。结果表明，与缓冲地块相比，以前使用的高分析肥料和改良剂会导致锌池中的锌显着枯竭。与未施肥的地块相比，农家肥（FYM）改良地块的所有锌库以及作物生产力和锌吸收量都明显更高。残留部分为主要形式，但发现有机结合和可交换形式在养分供应，作物生产力和养分吸收中起主要作用。相关和回归分析研究表明，有机形式是导致玉米和小麦作物单产和吸收变化的最重要因素。