IMPACT ON AGRICULTURE

Soil organic carbon is the basis of sustainable agriculture. Farmers are interested in retaining and increasing soil organic carbon for individual fields in order to improve soil health and yield. One of the main reasons behind this is the ability of soil organic carbon in maintaining the soil fertility. SOC improves soil aeration, water retention capacity, drainage, and enhances microbial growth. As carbon stored in the soil is increased carbon i “sequestered” (long -term storage) and risk of loss of nutrients through leaching and erosion is reduced. When the amount of carbon in the soil is increased it reduces the amount of carbon dioxide present in the atmosphere which provides a better climatic condition for plant growth. An increase in soil organic carbon results in more stable carbon cycle and enhanced overall agricultural productivity. 

DEPLETION OF SOIL ORGANIC CARBON

According to the study conducted in Sweden, nationwide the 270 TG c stocks in agriculture surface soil is rapidly decreasing at a rate of 1 TG per year. One of the reasons behind this according to the study of GUO and GIFFORD is change in land use pattern. There is a chance of reduction of 10% of c stock when there is change in land use from forest to crop land. Unsustainable management practices like excessive irrigation, over grazing, deforestation, excessive tillage, practice of burning agricultural fields also causes soc losses. A large amount of carbon in the soil is reduced due to plant harvesting processes. The process of decomposition done by micro-organisms present in the soil where half of the organic carbon is released in the form of carbon dioxide is a major reason behind soil organic carbon depletion. Greater root bio-mass also result in carbon loss due to increased rate of respiration that take place through these roots. The amount of organic carbon present in the soil is affected by factors like climate, texture, hydrology (water content), land use and vegetation. When the amount of carbon in soil is reduced it affects the ability of soil to supply nutrients to the plant which in turn leads to low yield and affect food security. It also reduces the soil bio-diversity since it effects the growth of microbes. Global warming also contributes in depletion of organic matter present in the soil.

NDRE OFFERS A SOLUTION

By substituting NDVI’s red band with NDRE’s red edge band we can mitigate this issue of saturation discussed abovev. NDRE’s red edge band provides a measurement that is not as strongly absorbed by just the topmost layers of leaves. By using NDRE, one can get better insight into crops in their later stage because it is able to observe further down into the canopy as well.

NDRE = (NIR – RE)/(NIR + RE)

NDRE is also less prone to saturation in the presence of dense vegetation. This will help us get much accurate results in pasture biomass estimation measurements. Thus, in situations like these, NDRE can provide a much accurate and better measurement of variability in an area in which the NDVI measurement would come simply as 1.0