By David Wall
Guest Columnist
Until the last few years, gardening or farming meant tilling the soil, and tilling is still the prevalent method. The last several years have seen a lot of justification for not tilling the soil. Each side has its proponents, with no till usually arguing its side the loudest.
No till definitely has some strong advantages. It keeps carbon in the soil instead of allowing it to be exposed, decaying faster, and freeing carbon back into the atmosphere. Proponents say you drive less over the soil, reducing soil compaction. Fuel consumption for tilling is eliminated, thus reducing costs. No till offers reduced erosion, while improving moisture conservation.
The advantages seem to point toward no till, but on the negative side, weeds still provide seeds, thus necessitating more herbicide use, and no till means more equipment. Additionally, new problems are coming to light.
First, soil compaction still occurs. It doesn’t show up at first, but over a 3-4 year period, it definitely occurs. On top of this, organic material over the same time period, is being concentrated in the top 2 ½” of soil rather than farther down where it’s needed. The result is that even if going no till, soil tilling is strongly recommended every 3-4 years.
At NE TX Community College, we’ve adopted a modified no till system dividing our garden into a recovery garden and producing garden. In the recovery half, we lay down 6” of mulch (April) and till it in…..twice, followed by planting cow peas, a legume, to increase nitrogen in the soil. In late summer, we mow the peas and plant a winter cover crop. In the producing half, vegetable crops are grown, laying down mulch around the plants, and ignoring weeds between rows. With sufficient water (drip irrigation) and nutrients, weeds don’t impact vegetable production.
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