Prospect of Strip Tillage in the Irrigated Desert Southwest.

Soil erosion by wind is widespread in the desert southwest, especially during the spring seasons, when farm lands have been prepared, ready for planting. The predominant tillage system (plowing and multiple disking) practiced in the area encourage accelerated erosion during high winds. Two reduced tillage systems (strip tillage and no-tillage) were compared to the conventional tillage practices in a sandy clay loam soil. Tillage treatments were established in a field which was previously sown to winter wheat (Triticum aestivum L.). The winter wheat crop was harvested as forage and baled, but a tall stubble (0.25 m high) was left, into which the tillage treatments were established. Tillage treatments included conventional tillage (CT) which involved five tillage passes to create a smooth seedbed across the entire plot; strip tillage (ST) which involved a single pass with a strip tiller creating a seedbed of about 0.2 m wide strips; and no tillage (NT) in which the land was left undisturbed. The test crop was corn silage (Zea mays L.). Corn growth and yields were assessed under each of the tillage treatments. Corn silage yields at 62% moisture content was 58.5 Mg/ha for CT treatment, 56.3 Mg/ha for ST and 46.4 Mg/ha for NT. These yield differences were not statistically significant.  However, when the net economic returns was calculated, which included the cost of tillage, ST gave higher net returns of about $37/ha more than CT and $500/ha more than NT. This study demonstrates that strip tillage can serve as a conservation tillage method in the irrigated desert southwest, capable of reducing soil degradation due to erosion, and enhancing farmers’ income.