Reduced-nutrient leachates in cash cover crop-soybean systems

摘要: Over-wintering crops are known to reduce nutrients in soil leachate spring, but little economic incentive is available grow these the Upper Midwest. New oilseed-bearing cash cover crops, such as winter camelina and pennycress, may provide needed incentives. However, abilities of sequester labile unknown. We used lysimeters buried at 30, 60, 100 cm examine nitrate reactive phosphorus (SRP) six soybean cropping system treatments: clean till, no-till, autumn-seeded radish, rye, camelina. Radish winter-killed naturally, rye was killed with a glyphosate, pennycress were allowed mature naturally after relay sowing soybean. Leachate chemistry studied for autumn, summer periods over two growing season. In leachates under radish tended have lowest levels. differences among levels across treatments greater than any other time period, values much lower treatments. summer, more uniform, occurring where grew best. general, like both environmental resources growers that they represent cash-generating grain nutrients, especially protect promote health from autumn through early summer.