Soil Mulching as an Important Element in the Strategy of Using Natural Water Resources in Agroecosystems of the Steppe Crimea

Resumo

Using the earlier developed MULCH model of heat-and-water exchange in the “soil–mulch cover–vegetation cover–land-surface atmosphere layer” system, we showed that the zero (minimum) tillage technology in combination with mulching the soil surface with plant residues is the most promising method for increasing the water availability and yield of wheat in steppe regions of the Crimea. It was found that the optimal thickness of the mulching layer on rainfed fields under wheat is ~4–5 cm. It was shown that minimum tillage in combination with mulching the soil surface with a 5-cm-thick layer of plant residues increases the water availability of wheat plants (which is determined by the ratio between the actual and potential transpiration of plants) on rainfed fields in the steppe regions of Crimea by 13% on the average. The yield of wheat increases compared to the conventional tillage practice (with consideration for the increase of humus content in the soil under long-term (about 8–10 years) mulching of soil surface) by 12% (~5.3 dt/ha) on the average. The obtained results can be used in the development of methods for using natural water resources in agroecosystems of the steppe Crimea.