Reduced-nutrient leachates in cash cover crop-soybean systems

Abstract

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

Root and Shoot Response to Nickel in Hyperaccumulator and Non-Hyperaccumulator Species

“…[ 111 ]. Pennycress exhibits winter growth and extreme cold tolerance traits [ 112 ] and it is known to provide ecosystem services in the cold season such as habitat and food source for pollinator insects, weed suppression, and reduction of soil erosion and nutrients leaching [ 109 , 113 , 114 , 115 , 116 ].…”

Translational genomics using Arabidopsis as a model enables the characterization of pennycress genes through forward and reverse genetics

“…(Phippen and Phippen, ; Johnson et al ., , ). Pennycress grown as a cover can reduce nutrient leaching and soil erosion and reduce the growth of spring weeds (Johnson et al ., ; Thom et al ., ). In addition, as an oilseed, pennycress holds great promise as a new cover crop that can provide an economic return to rural communities (Ott et al ., ).…”

Molecular tools enabling pennycress (Thlaspi arvense) as a model plant and oilseed cash cover crop

“…Pennycress possesses a unique combination of attributes including extreme cold tolerance, over‐wintering growth habit and early‐season maturity (Isbell, ). As a winter cover, pennycress provides important ecosystem services such as reductions in soil erosion and nutrients leaching, spring weed suppression, habitat for insects and an early‐season food source for pollinators (Eberle et al ., ; Groeneveld and Klein, ; Johnson et al ., ; Thom et al ., ; Thomas et al ., ).…”