Shallow Tillage with a Traditional West African Hoe to Conserve Soil Water
- W. A. Payne *a
Evaporation (E) from soil constitutes a large proportion of evapotranspiration (ET) of pearl millet [Pennisetum glaucum (L.) R. Br.] fields in West Africa. Reduced E would increase crop water supply and reduce the risk of resowing. We hypothesized that tillage after rain events with the hilaire, a traditional, shallow-cultivating hoe that pulverizes and darkens the soil surface, could conserve soil water and increase pearl millet yield. Experiments were conducted using bare and cropped plots. Tillage after rain (+ or −) was the only treatment for bare plots. Treatments for cropped plots were tillage after rain with the hilaire and fertilizer addition (12 kg ha−1 N and 12 kg P ha−1). For bare plots, tillage with the hilaire reduced soil surface reflectance by as much as ≈0.2 and increased soil temperature at 0.05 m by 12°C. Tillage increased soil water storage in the upper 2.4 m of bare plots by up to 47 mm. For cropped plots, tillage increased soil water storage in the upper 1.4 m by up to 32 mm, and it increased grain yield by 68% in 1991 and 70% in 1992. Fertilizer addition increased yield by 21% in 1991 and 116% in 1992. Tillage reduced ET in 1992 from 417 to 372 mm and increased water-use efficiency (WUEET) from 0.99 to 1.91 kg ha−1 mm−1 Fertilizer addition increased WUEET from 0.95 to 1.94 kg ha−1 mm−1 Practical exploitation of the hilaire's effect upon evaporation is not expected because it is a hand-operated tool. However, the study demonstrates principles upon which an animal-drawn implement might be designed.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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