A UC Davis publication reports that conservation tillage – the larger umbrella term under which the term “no till” conservation is defined – was defined in 1984 by the U.S. Soil Conservation Service (now the Natural Resources Conservation Service).

No till is a tillage system which maintains at least 30 percent of the soil surface covered by residue after planting, primarily where the objective is to reduce water erosion.

According to Mitchell and others, the objective of the residue left behind in the fields is to hold residual moisture and reduce the need for costly irrigation water.

Ramos confirmed this. He told attendees at a University of California-sponsored Cotton Field Day hosted at Lucero Farms about the appreciable decrease in water use on his no-till cotton field, compared to the minimally-tilled cotton planted in an adjacent field.

As of the end of May, Ramos had used four inches of water on the no-till plot and six inches in the minimum-till field.

Drip irrigation in Lucero’s cotton fields plays a vital role in controlling water usage, Ramos said. He rotates processing tomatoes and cotton. The drip irrigation has helped boost tomato yields by 20 percent.

Additionally, pests and weeds are less of a factor in the no-till system, according to several speakers at the field day. Ramos suspects the ground cover from the previous crops incorporated into the soil, and the agricultural residue on the surface, reduces weeds germination.

It was also suggested during the field day discussions that the arid environment above the soil surface, due to drip irrigation practices which release water where the plants need it the most, may play a positive role in pest management since pests do not like dry conditions on the soil surface.

Based on a UC Davis report, conservation tillage can reduce the number of times tractors cross farm fields. While this protects the soil from erosion and compaction, Mitchell says the erosion factor alone is just one of the larger, regional issues impacting California agriculture as dust and tractor emissions continue to become targets of state and federal regulators.

In no-till or direct seeding systems, the soil is left undisturbed from harvest to planting except perhaps for the injection of fertilizers, according to UC Davis. Soil disturbance occurs only at planting by coulters or seed disk openers on seeders or drills, and at that, the soil disturbance in planting under these systems is much less than traditional means, Mitchell says.