Abstract
This investigation was set up to study the effect of different levels of manure application from three sources, namely, cattle, sheep and poultry on rate of aggregate disintegration of a wide spectrum of soils with different textures. The drop test technique was followed to measure the rate of soil aggregate disintegration using three types of water (rainfall, spring and artificial saline waters). The results indicated there is a gradual increase the amount of energy required to disintegrate soil aggregates over a range of soil organic content from natural soil organic matter content to about 9%, beyond which a slight decrease in the amount of required energy was observed in most of the investigated soils. Among the manure sources sheep manure offered the highest performance. By contrast the cattle manure offered the least performance. The results also indicated that the amount of the required energy for disintegration tended to increase with clay content and with increase in the electrical conductivity of the applied waters. It can be concluded from the obtained results that the nearly all types of manures can be applied to reduce soil erosion risk up to an organic matter level of 9%. Additionally, there is no risk of soil sealing and erosion upon application of saline water with EC of < 2.2 dSm-1 via sprinkle irrigation.
