Effect of land-use change along altitudinal gradients on soil micronutrients in the mountain ecosystem of Indian (Eastern) Himalaya

Abstract

Management of soil micronutrients for better crop production needs a sound understanding of their status and causes of variability. This is more relevant for acid soils of the mountain ecosystem of Eastern Himalaya (Northeast India). We assessed the status, and the effect of land uses along altitudinal gradients (14 to 4090 masl) on soil properties and micronutrient concentrations (DTPA extractable Fe, Mn, Cu, and Zn) across the region. Soils varied widely in micronutrient concentrations: Fe from 0.665 to 257.1 mg kg−1 while Mn, Cu, and Zn from traces to 93.4, 17.1, and 34.2 mg kg−1, respectively. On conversion of evergreen forests (EF) to upland agriculture (Shifting—SC and Settled—SA) and plantation (PH), Mn, Cu, and Zn concentrations decreased significantly from 30.5, 1.74, and 2.13 mg kg−1 to 6.44–17.8, 0.68–0.81, and 1.06–1.42 mg kg−1, respectively. Grassland (GL) and lowland paddy (LP) had comparable Fe, Mn, and Cu concentrations (except Zn). Degradation of EF to scrubland (SL) recorded the lowest Mn (5.91 mg kg−1), Cu (0.59 mg kg−1), and Zn (0.68 mg kg−1) concentrations. Fe concentration was however increased in degraded SL (+ 73%) over EF (48.7 mg kg−1). The distribution of micronutrients among the land uses was inconsistent and followed the order: (i) Fe: SL > PH > LP > EF > GL > SC > SA, (ii) Mn: EF > GL > LP > PH > SC > SA > SL; (iii) Cu: EF > GL > LP > SC > SA = PH > SL; and (iv) Zn: GL > EF > LP > SC > SA > PH > SL. Four micronutrients responded differently and followed a non-linear, 6th—order polynomial trend along the altitudinal gradients (< 500 to 4100 masl). Peak concentrations of Fe, Mn, and Cu were recorded at 1001–2000 m while Zn was recorded at > 4000 masl. The variability (54–64%) in soil micronutrients was mainly controlled by three key soil properties: acidity, clay, and organic carbon contents. Thus, altitude-specific land-use management holds significance in the distribution of available soil micronutrients in hilly ecosystems.

Soils in warmer and less developed countries have less micronutrients globally

“…Until now, three factors have restricted our understanding of the global distribution and ecological drivers of soil micronutrients. First, previous studies have focused on distribution at national/local scale and primarily within agricultural systems (Ballabio et al, 2018; Hengl, Leenaars, et al, 2017; Navarro‐Pedreño et al, 2018; Ramzan & Wani, 2018; White & Zasoski, 1999), revealing a wide range of environmental drivers, from soil parameters (e.g., texture; Kabata‐Pendias & Pendias, 2001; McBride, 1989; Shuman, 2005) to climate (Moreno‐Jiménez et al, 2019; Tan et al, 2020), parent material (Augusto et al, 2017; Kabata‐Pendias & Pendias, 2001; Luo et al, 2016; Moreno‐Jiménez et al, 2019) and biota (Choudhury et al, 2021; Hemkemeyer et al, 2021) that operate in different regions. As such, we lack an unifying perspective of the variation in micronutrient abundance in soils at global scale, covering large terrestrial climatic and vegetation gradients.…”

Impact of land-use systems on fertility parameters and deterioration indices of soil in the sub humid Southern Plains of Rajasthan, India

“…Higher amount of micronutrients was observed under agricultural and agri-horticultural lands than barren land, due to the regular addition of crop residues and fertilizers/manures. While the lesser amount of soil micronutrients in the barren land could be due to erosional loss, poor soil aggregation, and low organic carbon content (Dhaliwal et al, 2008;Chaudhury et al, 2021). On the other hand, regular crop harvest, exhaustive cultivation, and consistent disturbances during various soil management practices are the reason behind the lesser content of soil micronutrients in the agricultural and agri-horticulture landuses than forest, grass, and horticultural LUSs.…”

Integrating conservation agriculture with intensive crop diversification in the maize-based organic system: Impact on sustaining food and nutritional security

“…Maize is grown with moderate to minimal tillage on slopes/ terraces. Intensive tillage practices and improper crop management can negatively influence soil quality and potentially cause soil degradation (6,9,10). More resource-efficient practices, such as conservation agriculture with full retention of crop residue and diversified crop rotations, are receiving widespread support as potential solutions for lowering the consumption of non-renewable resources, reversing soil deterioration, and restoring soil quality, all while cutting emissions (11)(12)(13)(14).…”