Improving Soil Water Availability through the Use of Cover Crops in Agriculture: Modelling Soil Moisture on Cover Crops.

Improving soil water availability through the use of cover crops in agriculture: Modelling soil moisture status under cover crops. Manuel E Camacho, Chris Reberg-Horton, Steven Mirsky, Harry Schomberg, and Dennis Timlin. Abstract Cover crops have been widely used in sustainable agriculture due multiple benefits associated, among them weed control, reduction in soil erosion, enhancing C and N content on the soil as well as improving soil water infiltration by runoff reduction and stability aggregation. Nevertheless, the effects of cover crops on soil water availability have not been studied deeply. For the above, present work was conducted aiming to model soil moisture status under cover crops and to determine their possible improvement on soil water availability. A total of 34 farms from North Carolina, Maryland and Georgia were used. Two treatments were stablished: 1) soil under cover crop (CC) and 2) bare soil (BS), using corn (Zea mayz L.) as indicator crop. Soil samples were taken in both treatments to determine soil texture, bulk density, soil porosity and C/N content at three depths: 0-30 cm, 30-60 cm and 60-100 cm. TDR sensors were installed at three depths: 15, 45 and 80 cm in both treatments. Therefore a model was developed to estimate soil water availability. Soils under cover crop treatment (CC) showed a trend to obtain higher values of volumetric moisture (%) than bare soil (BS) in three depths evaluated, especially in 45 and 80 cm depth in clayey soils. On high events of rainfall (>15 mm) during early season, it was found a trend of CC to keep higher values of soil volumetric moisture on first 30 cm depth than BS, where soil moisture showed a trend to decrease.