Soil Aeration under Different Soil Surface Conditions

The assessment of the importance of soil aeration for various plant characteristics and environmental conditions is necessary to evaluate the oxygen relations to the crops. The root environment as a solid-liquid matrix depends upon soil structure and moisture condition. A limited oxygen supply restricts the root development and also reduces the nitrogen fixation in peanuts. Soil surface conditions can be altered by mulching and plays a significant role in protecting the plants against deficient aeration during critical periods of growth phases. The effects of eight mulching treatments (rice husk, rice husk-incorporated, paddy straw, sawdust, water mulch, clear polyethylene, black polyethylene and control) on the soil oxygen diffusion rate (ODR) during the various growth phases of peanut crop ( Arachis hypogaea L.) were investigated on a lateritic sandy loam soil (ultisols). These experiments were conducted for two consecutive seasons. ODR values were higher in mulched plots. With the progress of growth stages and also in deeper soil depths, the differences between the values of ODR among treatments narrowed down. The influence of mulches on other physical edaphic properties like bulk density, aeration (noncapillary) porosity and soil temperature were also studied. Mulches reduced the surface crusting and thereby soil bulk density; and increased the aeration porosity and ODR. Soil temperature was higher under plastic mulches whereas vegetative mulches suppressed it.