Soil and Water Conservation Guide
Soil not only provides anchorage to plants but all nutrients and water are absorbed into the plants through the soil. Therefore, all cultural practices in crop production are directed toward improvement and maintenance of the physical condition of the soil so as to create a favorable condition for the growth and development of crop plants.
Water is indispensable for growth and development of plants, too much or too little water, decide between success and failure of crop production enterprise. In this article, you would treat the different methods of soil and water conservation.
Principles of Soil and Water Conservation
The principle of soil and water conservation is basically that of reducing run- off, percolation and evaporation losses. Essentially, water management entails three basic practices:
Conservation of natural precipitation (in sub humid and arid regions);
Drainage of wet lands;
Supplementation of rainfall with irrigation.
Methods of Water Conservation
Water generally is a limiting factor for crop production where irrigation is not available. It can be limiting even in humid and sub-humid regions where there is a theoretical need to dispose of excess water.
Dry periods with water deficit frequently occur in these regions and positive responses to moisture conservation techniques are commonly obtained. Over 80% of the agricultural land of the world is not irrigated.
In rain fed systems the constraint is not only the erratic rainfall distribution but the amount of rainfall that can be stored in the root zone.
Mulches and Green Manures
Mulch may be defined as a protective covering over the soil surface that is intended to minimize evaporation losses. Green manures may serve as mulches. Leaves, straw and saw dust are also commonly used. Paper and plastics may also be used.
Importance of Mulch
Mulch intercepts solar radiation, reflects the light and so keeps the soil temperature low.
It reduces the effect of wind and air movement.
The presence of mulch on the surface of the soil improves infiltration because they reduce the impact of raindrops.
Reduces run-off losses.
Read Also : Types of Seed Germination, Seed Emergence and Seedling Vigour
1. Run-off control
Run-off occurs when rainfall intensity exceeds the infiltration capacity of the soil which is a measure of the ability of the soil to absorb and transmit rain water. Run-off is limited on soils with a high infiltration capacity.
This in turn depends on the water transmission characteristics and structural stability of the soil and its ability to maintain continuous pores.
The transmission pores may exist in the soil as a result of coarse texture, good aggregation, or from the burrowing activities of the soil fauna, particularly certain species of earthworms.
The rate and amount of run-off are also influenced by the intensity and amount of rainfall received, the previous soil moisture content, the degree of relief, slope steepness and aspect.
These factors manifest themselves in a wide range of run-off management problems and conservation needs.
Ways of Minimizing Run-Off
- Careful and rational management of crop residues
- Terraces and contouring
- Strip cropping and ridging.
This is one of the most effective water conservation techniques particularly in areas of limited rainfall.
It is the practice of leaving the land unplanted in alternate years or cropping the land for three years and then fallowing for the next few years.
In general, the moisture saved in this way is small but it may be critical in dry-land farming.
b. Terraces and contouring
These are methods of minimizing the loss of surface water which may occur when water gushes down slopes after intense rainfall or excessive irrigation.
c. Contour farming
This is the practice of cultivating and planting on strips of land that are of the same elevation.
The system of gently sloping terraces separated from each other by banks helps to hold water on the soil surface and so encourage infiltration.
In preventing run-off, contour farming and terraces also reduces soil erosion which will remove valuable nutrients from the topsoil.
d. Strip cropping
Spreading vegetation or crops are established in a strip which is at right angles to the flow of water or the prevailing wind. This gives protection to adjacent strip or rows of crops or fallow land.
Field strip cropping: Crops are grown in strips across the general slope of the land but not following the contour. Spreading crops or grass may be alternated with more upright crops.
Contour strip cropping: Crops are grown in relatively narrow strips which are planted on the contour and at right angles to the natural direction of the slope. Crops are usually planted in strips of grass.
Wind strip cropping: Crop strip are planted which are at right angle to the prevailing winds irrespective of the contour of land. The crops serve as series of miniature windbreaks to minimize wind damage.
Ridges help surface drainage during rains and prevent young plants from being washed away. Ridges are formed by pilling up top soil so the depth of soil for plant roots to grow is increased.
Read Also : The Major Effects of Water Pollution
Do you have any questions, suggestions, or other contributions? Kindly use the comment box provided below for all your contributions. You are also encouraged to please kindly share this article with others you feel can benefit from this information if found useful enough as we may not be able to reach everyone at the same time. Thank you so much for sharing!
Have you visited our Market Place Today? Follow this link to visit Agric4profits.com Market Place now to check out our affordable products & services that might interest you and solve your current needs at a very cheap price.