Using Cover Crops to Potentially Solve Environmental Issues.

Cover crops have potential to remediate several environmental issues including reducing soil erosion and sediment losses, reducing nitrogen and phosphorus runoff from fertilizer or manure, improving water infiltration, increasing carbon sequestration, increasing soil’s water holding capacity, and improving saline/sodic soils. Literature review shows that cover crops reduce soil erosion and sedimentation by 57-96%.  Reductions in soil erosion depend upon species, date of planting, cover crop density and height, and rainfall intensity.  Gramineae cover crop species may reduce nitrogen losses by 55-85% and increase phosphorus uptake up 22.4-67.3 kg/ha or approximately 0.2% of their biomass. Reductions in soil phosphorus due to cover crops may be related more to the benefits associated with increased water infiltration and improved soil structure than phosphorus runoff. Ohio research shows nitrogen uptake of 3.5-5.3% by Brassica and Gramineae species. Gramineae species (Secale cereale, Triticosecale, Lolium multiflorum Lam. and Avena sativa) are being used in Ohio as part of a Lake Erie initiative to reduce soluble reactive phosphorus in surface water from fertilizer and manure. Water infiltration rates increased by a factor of 2-3 times comparing winter cover crops to conventional tillage. Increased carbon sequestration improves water holding capacity from 125-254 kilo liters per 30 cm of soil ha^-1 in a sandy soil for every 1% increase in soil organic matter to 203-482 kilo liters per 30 cm of soil ha^-1 for a silt loam soil. Due to increased water infiltration and improved water storage capacity, crops have more water available to increase yields. On saline/sodic soils, Gramineae cover crops are being used to prevent salt accumulation in low lying areas and the improvement in SOM assists in buffering the soil. In summary, planting cover crops and the addition of live plants grown year round in the ecosystem helps to remediate many natural soil issues.