Singh Ashutosh Kumar, Rai Apurva, Pandey Vivek, Singh Nandita
Academy of Scientific and Innovative Research (AcSIR), CSIR-National Botanical Research Institute (CSIR-NBRI) Campus, Rana Pratap Marg, Lucknow, 226001, India; Plant Ecology and Environmental Science Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India.
Plant Ecology and Environmental Science Division, CSIR-National Botanical Research Institute, Lucknow, 226001, India; Department of Botany, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India.
J Environ Manage. 2017 May 1;192:142-149. doi: 10.1016/j.jenvman.2017.01.041. Epub 2017 Feb 1.
Glomalin related soil protein (GRSP) is a hydrophobic glycoprotein that is significant for soil organic carbon (SOC) persistence and sequestration, owing to its large contribution to SOC pool and long turnover time. However, the contribution of GRSP to dissolve OC (DOC) leach from soil is not yet comprehensively explored, though it could have implication in understanding SOC dynamics. We, therefore, aim to measure the contribution of GRSP to DOC, in a range of land uses and climatic seasons in the dry tropical ecosystem. Our results demonstrated that a significant proportion of GRSP (water soluble GRSP; WS-GRSP) leached with DOC (7.9-21.9 mg kg), which accounts for 0.2-0.23% of soils total GRSP (T-GRSP). Forest exhibited significantly higher WS-GRSP and DOC leaching than fallow and agriculture. WS-GRSP and DOC accumulations were higher in the dry season (summer and winter) than in rainy. The extent of seasonal variations was higher in forest than in other two land uses, indicating the role of vegetation and biological activity in soil dissolve organic matter (DOM) dynamics. The regression analysis among WS-GRSP, T-GRSP, DOC and SOC prove that the accumulations and leaching of GRSP and other soil OM (SOM) depend on similar factors. The ratio of WS-GRSP-C to DOC was higher in agriculture soil than in forest and fallow, likely a consequence of altered soil chemistry, and organic matter quantity and quality due to soil management practices. Multivariate analysis reflects a strong linkage among GRSP and SOC storage and leaching, soil nutrients (nitrogen and phosphorus) and other important soil properties (pH and bulk density), suggesting that improving GRSP and other SOM status is an urgent need for the both SOC sequestration and soil health in dry tropical agro-ecosystems.
球囊霉素相关土壤蛋白（GRSP）是一种疏水糖蛋白，由于其对土壤有机碳（SOC）库的巨大贡献和较长的周转时间，对土壤有机碳的持久性和固存具有重要意义。然而，尽管GRSP对土壤溶解有机碳（DOC）淋失的贡献可能对理解SOC动态有影响，但尚未得到全面研究。因此，我们旨在测量在干旱热带生态系统的一系列土地利用类型和气候季节中GRSP对DOC的贡献。我们的结果表明，相当一部分GRSP（水溶性GRSP；WS-GRSP）与DOC一起淋失（7.9 - 21.9毫克/千克），占土壤总GRSP（T-GRSP）的0.2 - 0.23%。森林中WS-GRSP和DOC的淋失量显著高于休耕地和农田。旱季（夏季和冬季）的WS-GRSP和DOC积累量高于雨季。森林中季节变化的程度高于其他两种土地利用类型，表明植被和生物活性在土壤溶解有机质（DOM）动态中的作用。WS-GRSP、T-GRSP、DOC和SOC之间的回归分析证明，GRSP和其他土壤有机质（SOM）的积累和淋失取决于相似的因素。农业土壤中WS-GRSP-C与DOC的比值高于森林和休耕地，这可能是由于土壤管理措施导致土壤化学性质、有机质数量和质量改变的结果。多变量分析反映了GRSP与SOC储存和淋失、土壤养分（氮和磷）以及其他重要土壤性质（pH和容重）之间的紧密联系，表明改善GRSP和其他SOM状况对于干旱热带农业生态系统中的SOC固存和土壤健康都至关重要。
