Soil health: Which is more important, soil moisture or organic fertilization?

Water shortage is a significant issue faced by agricultural areas in the Mediterranean area. With current available water levels below 300 mm per year, this situation is progressively getting worse as a result of climate change. 

The microbial community is an essential component of the soil, performing a wide range of functions, from organic matter degradation to nutrient cycling and aggregate formation. Soil microbial communities are very sensitive to changes in the soil, such as perturbations in irrigation water and land cultivation, and are thus considered as possible indicators of soil health.

A scarcity of water reduces soil organic C, altering the soil microbial community structure and agricultural management practices such as the use of herbicides and intensive ploughing can significantly alter the structure of microbial soil communities and modify the soil ecosystem, influencing soil productivity and quality. Herbicides, fertilizers, fungicides and insecticides have also affected the water storage capacity of soil, in addition to soil biota and the function and structure of soil microbial communities, with implications for water and soil quality. 

Sustainable agriculture and improved water management strategies are needed to prevent the depletion of agricultural soil ecosystems in semi-arid areas, but which is more important, moisture or organic matter

Both carry weight in improving the properties of the soil. Increasing the water content of the soil, by drip irrigation, can help maintain the biological and chemical fertility of soils in agroecosystems under semiarid conditions, but also the use of organic fertilization. By controlling irrigation doses and applying organic amendments, it may be possible to increase the microbial abundance and function in soil and support greater fertility of soils.

SOURCE: Department of Agrochemistry and Environment of the University Miguel Hernandez