February 26, 2007	Monday	Safar 8, 1428

RESOURCES are always limited and they need to be conserved to achieve sustainability in any system. Mulches can be successfully employed for resource conservation and sustainability in agriculture.

Mulch is a covering of natural or artificial material spread over the soil. Mulch can prove helpful in accomplishing various objectives such as weed control, moisture conservation, addition of organic matter to the soil, regulating soil temperature, repel insects, and control of soil erosion.

Natural materials for mulching include straw, leaves, hay, farm residues, compost, bark, saw dust, and even wool, while the artificial mulches include plastic mulch, organic sheet mulch, rock and gravel etc. Organic sheet mulch has the advantage of being biodegradable over the plastic sheet mulch which is difficult to be disposed of. Mulches are easily applied at the beginning of the growing season and can also be reapplied during the growing season if required.

Weeds compete with the crop plants for light, space, water and nutrients. Mulches can be manipulated to suppress weeds and thus conserve these resources for use by crop plants. Black plastic mulch stops the weed germination by blocking the sunlight to reach the weed seeds and also suppresses the weeds physically. Farm residues have the additional advantage of excreting certain chemicals to inhibit the weeds.

Water is most critical for plant growth. Moisture conservation is needed due to acute water shortage in the world as well as Pakistan. Mulch reduces the evaporation losses from the soil surface conserving the water. Water use efficiency is greatly enhanced by using mulches.

Mulches of organic or plant origin degrade slowly to add organic matter to the soil. The micro environment produced by the natural material fastens the microbial activities in the soil to increase productivity.

Mulches play an important role for temperature regulation of the soil by retaining more heat in winter to warm the soil surface. They also act as insect repellent. Soil erosion is a serious threat that reduces the fertility of the soil by eroding the fine soil particles. If the soil is provided with some protective mulch material, the soil degradation can be controlled.

There is a need to make the farming community aware about the benefits, resulting from the application of mulches in an agricultural production system. The use of mulches in almost all the agricultural production systems is easy, feasible and economical, returning high benefits to growers.