Why are cash crops important

The high residue cultivator: weed rescue for no-till systems

[youtube https://www.youtube.com/watch?v=BbcSQktWInQ&w=1200]

Continuously organic no-till is still seen as unattainable. However, options to reduce tillage in the Mid-Atlantic were identified and tried, including: (1) rotation of annual grain crops with perennial forage; (2) reducing the depth and degree of soil inversion (e.g., chisel plows and discs instead of the share plow); or (3) direct sowing of monetary crops in cover crops that are mechanically killed.

Cover crop-based organic rotary no-till crop systems have focused on corn and soybean production in the mid-Atlantic. Soybeans are typically not planted in a cereal-rye cover crop planted in the fall, while corn is more commonly planted in a hairy vetch cover crop planted in the fall.

Rodale Institute uses the roller crimper as the primary weed control tool in organic rotary no-tillage for corn and soybeans. With this method, a dense cover is rolled at the same time and a cash crop is planted in the mulch layer using a modified no-till planter. The chevron shape of the crimper blades ensures that the stems of the cover crop are broken in so many places that they can no longer recover, creating an evenly distributed layer of mulch.

In normal years, the thick mulch suppresses the weeding season for a long time. However, unexpected weather conditions such as high rainfall at the time of ripple, planting the cover crop late in the fall, or rolling the cover crop before the effective demolition growth stage, which is usually flowering or anthesis, can result in significant weed infestation results.

An innovative tractor-mounted device called a residue-rich cultivator is used as a "rescue response" to control weeds in a rotating no-till system. The residue-rich cultivator has shares (residue cutters) that cut through the residue mulch of the cover crop to create a path for the sweepers to ride under the mulch just below the surface of the soil to cut weed tops from their roots or uproot them. Two press wheels on either side of the share press firmly on mulch debris, making it easier to cut the debris cleanly, ensuring that the sweepers driving under the mulch leave the mulch intact and relatively undisturbed. This is important to ensure that the mulch does not interfere with weed control.

Dr. Emmanuel Omondi is the director of the Farming Systems Trial.

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