Land-use change significantly impacts soil micro-nutrients distribution and transformations due to their inefficient scale- and location-specific management in different ecosystems. We studied the changes in micro-nutrients (viz. Zn, Cu, Fe and Mn) availability and their transformations in soils of hilly landscapes under five distinct land-use systems including mono cropping, double cropping, agroforestry, orchards and the vegetable crops to explore relationship between different fractions of variable solubility and their mobility in response to land-use change. Among the compared land-use systems, DTPA-Zn, Fe, Mn and Cu comprised ~ 3.0 to 8.2%, ~ 0.21 to 0.35%, ~ 1.2 to 6.3% and ~ 7.6 to 17.5% of their respective total content in soils. The agroforestry system had significantly (p < 0.05) higher DTPA-Zn and Mn, compared with mono-and double cropping system. However, the orchard soils had ~ 2.1, 2.0 and 3.4-times higher DTPA-Zn, Fe and Cu concentration than the agroforestry system. The agroforestry system was distinct with significantly highest proportion of total Cu retrieved as amorphous oxide bound (~ 20.5%), crystalline oxide bound (~ 33.6%), organic matter bound (~ 2.1%), while the lowest proportion was accumulated as residual form (~ 43.8%), compared with the other studied land-use systems. The mobility factor that explicit micro-nutrient transformations among soluble and stable pool revealed that monocropping had the significantly lowest (~ 3.3%), while the agroforestry system had the highest Zn mobility factor (~ 4.9%). On the other hand, agroforestry system had significantly lowest (~ 1.8%), while the soils under vegetable crops had the highest Mn mobility factor (~ 7.5%). The principle component analysis (PCA) elucidated residual micro-nutrient (Zn, Fe and Mn) fraction as significant contributors to discern land-use change in fragile hilly landscapes. These results highlight the importance of micro-nutrients management through robust interventions for long-term sustainability different land-use systems in a cold high altitude Himalayan mountainous region.

土地利用变化由于对不同生态系统的规模和位置特定的管理效率低下，极大地影响了土壤微营养素的分配和转化。我们研究了五种不同土地利用系统（包括单季种植，双季种植，农林业，果园和蔬菜作物）对微量营养素（锌，铜，铁和锰）有效性的变化及其在丘陵景观土壤中的转化。探索可变溶解度的不同部分与它们对土地利用变化的响应之间的关系。在比较的土地利用系统中，DTPA-Zn，Fe，Mn和Cu占土壤各自总含量的〜3.0至8.2％，〜0.21至0.35％，〜1.2至6.3％和〜7.6至17.5％。农林复合系统显着（p <0.05），与单作和双作系统相比，DTPA-Zn和Mn含量更高。然而，果园土壤的DTPA-Zn，Fe和Cu浓度比农林业系统高约2.1、2.0和3.4倍。农林业体系与众不同，以无定形氧化物结合（〜20.5％），结晶氧化物结合（〜33.6％），有机物结合（〜2.1％）的方式回收的总铜中比例最高，而最低的则以残留形式积累（〜43.8％），与其他研究的土地利用系统相比。可溶性和稳定库之间显着的微量营养元素转化的迁移因子表明，单作作物的锌迁移因子最高（〜3.3％），最低（〜3.3％），而农林业系统的锌迁移因子最高（〜4.9％）。另一方面，农林业系统的比例最低（〜1.8％），而蔬菜作物下的土壤中锰的迁移率最高（〜7.5％）。主成分分析（PCA）阐明了残留的微量养分（Zn，Fe和Mn），这是识别脆弱的丘陵景观中土地利用变化的重要因素。这些结果凸显了通过强有力的干预措施来管理微量营养素的重要性，以实现寒冷高海拔地区不同土地利用系统的长期可持续发展喜马拉雅山区。