Environmental Monitoring of Biochemical Compounds of Selected Crops in relation to Soil Quality of Agricultural Ecosystem

The present research work was carried out from January to April (2014) in rural agricultural ecosystem of Central Gujarat (India). The main aim of this pilot-scale study was to evaluate the interrelationship between selected crops in terms of fortnightly variation of geochemical characters of agricultural soils of three different crop fields, along with selected crops e.g. Tomato (Solanum lycopersicum) (TM), Wheat (Triticum aestivum) (WH) and Tobacco (Nicotiana tabacum) (TB). To determine the soil quality, geochemical parameters such as Temperature, pH, Phenolphthalein Alkalinity (PA), Total Alkalinity (TA), Carbonates, Bicarbonates, Total Hardness (TH), Calcium (Ca), Magnesium (Mg), Chloride, Sulphate, Phosphate, Nitrate, Total Organic Carbon (TOC), Total Organic Matter (TOM), Chromium (Cr) and Ferrous (Fe) were analyzed. On the other hand, the biochemical profile of selected crops was determined by estimating the contents of specific metabolites like Carbohydrates (CB), Proteins (PR), Amino Acids (AA), and Phenols (Ph). The findings of the present study revealed the highest concentration of (1) pH, TOC and TOM in TM soil, (2) TH, Ca, Sulphate, Nitrate, and Cr in WH soil, and (3) TA, Bicarbonates, Mg, Chloride, Phosphate, and Fe in TB soil. In case of TM, leaf exhibited maximum amount of CB and Ph, while PR and AA were more in stem. In WH, CB was highest in leaf, whereas PR, AA, and Ph were utmost in stem. In TB, leaf exhibited peak amount of CB, PR, and Ph, while AA was more in stem. Among all plant-parts, roots showed the least contents of all the studied metabolites. Overall, CB and Ph were more in TB, while WH was rich in terms of PR and AA. Thus, as a whole TM was found to contain comparatively less amount of all the studied biochemical compounds. Moreover, Correlation Coefficient Matrix (r) between geochemical parameters and biochemical compounds revealed the strong positive correlation between CB and Nitrate, PR and Chloride, AA and Mg, and Ph and Cr in TM. In case of WH, CB was found to be affected by the presence of Fe, PR and AA by Mg, and Ph by Chloride. While in case of TB, CB and PR were found to be influenced by pH, and AA and Ph by Sulphate. The findings of the present study can be earmarked for the peasants to use soil-friendly biofertilizers and metabolite-targeted biopesticides to enhance the crop biomass, productivity, and yield. Further study is in line to develop an interrelationship between soil qualities of different crop fields with other metabolites (upto secondary level) of commercial crops, cash crops, plantation crops, food grains, vegetables, and fruits of the region to draw out remarkable and implementable observations, which may be useful by agricultural practitioners of Central Gujarat to revive the agricultural economy of the region.本研究于2014年1-4月在印度古吉拉特邦中部的农村农业生态系统中开展。本项中试规模研究的核心目标为：针对三处不同农田的农业土壤，结合所选的三种作物（即番茄（Solanum lycopersicum，TM）、小麦（Triticum aestivum，WH）与烟草（Nicotiana tabacum，TB）），以每两周为周期的土壤地球化学特征变化为维度，评估不同作物间的相互关联。为表征土壤质量，本研究分析了多项地球化学参数，包括温度、pH值、酚酞碱度（Phenolphthalein Alkalinity，PA）、总碱度（Total Alkalinity，TA）、碳酸盐、碳酸氢盐、总硬度（Total Hardness，TH）、钙（Calcium，Ca）、镁（Magnesium，Mg）、氯化物、硫酸盐、磷酸盐、硝酸盐、总有机碳（Total Organic Carbon，TOC）、总有机质（Total Organic Matter，TOM）、铬（Chromium，Cr）与亚铁（Ferrous，Fe）。另一方面，通过测定特定代谢物含量以明确所选作物的生化特征，所测代谢物包括碳水化合物（Carbohydrates，CB）、蛋白质（Proteins，PR）、氨基酸（Amino Acids，AA）与酚类物质（Phenols，Ph）。本研究结果显示：（1）TM组农田土壤的pH值、总有机碳（TOC）与总有机质（TOM）含量最高；（2）WH组农田土壤的总硬度（TH）、钙（Ca）、硫酸盐、硝酸盐与铬（Cr）含量最高；（3）TB组农田土壤的总碱度（TA）、碳酸氢盐、镁（Mg）、氯化物、磷酸盐与亚铁（Fe）含量最高。就TM组作物而言，叶片中的碳水化合物（CB）与酚类物质（Ph）含量最高，而茎秆中蛋白质（PR）与氨基酸（AA）含量更丰富；WH组作物的叶片中碳水化合物（CB）含量最高，茎秆则蛋白质（PR）、氨基酸（AA）与酚类物质（Ph）含量达峰值；TB组作物的叶片中碳水化合物（CB）、蛋白质（PR）与酚类物质（Ph）含量最高，而茎秆中氨基酸（AA）含量更高。在所有植物组织中，根部的所有被测代谢物含量均为最低。整体而言，TB组作物的碳水化合物（CB）与酚类物质（Ph）含量更高，WH组作物则富含蛋白质（PR）与氨基酸（AA）；而TM组作物的所有被测生化化合物含量相对最低。此外，地球化学参数与生化化合物间的相关系数矩阵（r）结果显示：TM组中，碳水化合物（CB）与硝酸盐、蛋白质（PR）与氯化物、氨基酸（AA）与镁（Mg）、酚类物质（Ph）与铬（Cr）均呈显著正相关；WH组中，碳水化合物（CB）含量受铁（Fe）含量影响，蛋白质（PR）与氨基酸（AA）含量受镁（Mg）含量影响，酚类物质（Ph）含量则受氯化物影响；TB组中，碳水化合物（CB）与蛋白质（PR）含量受pH值影响，氨基酸（AA）与酚类物质（Ph）含量受硫酸盐影响。本研究结果可为农户提供指导，助力其施用亲土型生物肥料与靶向代谢物生物农药，以提升作物生物量、生长性能与产量。后续研究将进一步探究本区域不同农田土壤质量与商品作物、经济作物、种植作物、粮食作物、蔬菜及水果的其他代谢物（可达次生代谢物水平）间的关联，以期得出具有实际应用价值的显著结论，助力古吉拉特邦中部的农业从业者重振区域农业经济。