Cotton growers in the southeastern U.S. can deal with periodic droughts by using conservation tillage and fertilizing with poultry litter, Agricultural Research Service (ARS) scientists report.
Agricultural engineer Dinku Endale and agroecosystems ecologist Harry Schomberg at the ARS J. Phil Campbell, Sr., Natural Resource Conservation Center in Watkinsville, GA, conducted a study that found no-till cotton fertilized with poultry litter yielded 42% more than conventionally tilled cotton fertilized with ammonium nitrate.
Using no-till practices alone increased yield by 33% over conventional tillage practices, they found.
According to Endale, many soils in the southeastern states have low water-holding capacity and form nearly impervious layers that restrict root growth. If roots can't penetrate deeply enough to access soil water reserves, the drought effect is worsened.
No-till cotton was able to capitalize on carryover water in the soil, faring better after being established. That helped it to survive into the blooming phase. Conservation tillage protects the soil surface and allows more rainwater to penetrate.
Long-term use of practices such as no-till allows crop residue to accumulate on soil surfaces, which helps build soil structure, increases rainwater filtration, reduces evaporation and increases the biological activity that helps improve nutrient cycling.