"ZERO TILLAGE"

M.R. CHAUDHRY
Oct 22 - 28, 2007

"Zero tillage" is an effective and useful approach to conserve resources. It has been realized by the agriculture scientists that resources are limited and man can only conserve them. Availability of farm inputs at right time and in proper quantity is important and necessary for agriculture. To meet the ever-increasing food demands in accordance with the increase in the world's population, the solution lies in getting maximum production from land resources, for which all available factors of production must be combined in such a way that maximum quantity and quality could be achieved.

The importance of wheat as a major cereal crop and a staple food for Pakistan cannot be neglected. Wheat import for domestic need proves not only costly it overburdens our economy. This is natural that agriculture depends upon the environment and nothing can easily be said with accuracy about the outcome of its success. At times wheat production goes beyond the target while it fails to fulfill even domestic consumption needs. Thus agricultural production depends very much on the environmental conditions. The government should formulate policies with a provision for resource conservation technology to achieve higher production targets. The Zero tillage is one of the few technologies to be practiced for rice growing districts and could be beneficial for achieving good yields in less time and with less cost.

Rice is an important cereal crop of upper Punjab but is also cultivated in some areas of Sindh. This crop in Pakistan on an average requires 16-18 irrigations. After rice harvest, the moisture in soil is enough for sowing the next crop i.e. wheat. If rice is harvested late, wheat sowing also gets delayed. Wheat production is sensitive in relation to sowing time. The conventional operations further delay the sowing of wheat, which result in decrease in yield. Instead if Zero tillage is used then timely sowing of the wheat crop would be achieved and the yield enhanced. Besides timely sowing of wheat crop, Zero tillage technology can further benefit farmers.

It would be worth-mentioning that the area under rice and wheat has stabilized and further expansion seems unlikely. At the same time it has been noticed that growth in cereal yields has begun to slow in many high potential agricultural areas, owing to soil nutrient deficiency, declining levels of organic matter, increasing salinity, falling water tables and the build-up of weeds, pathogens and pest pollutions. The necessity does not lie in more irrigation and chemical fertilizers. Instead recent research indicates, farmer could produce more and help to conserve natural resource base - by abandoning current land ploughing and harrowing practices in favour of "Zero tillage". The simple technique of drilling seed into the soil with little or no prior land preparation.

FAO says that conventional tillage with tractors and ploughs is a major cause of severe soil loss in many developing countries. In the past it was thought that tbe more you till the soil, the more yield you get. The truth is that more tillage causes more erosion and soil degradation, especially in warmer areas where the topsoil layer is thin. The most desirable tillage is to leave a protective blanket of leaves, stems and stalks from the previous crop on the surface. Zero tillage systems provide higher yields at less cost and also save on fuel use and tractor wear and tear.

Using innovative ways China has reduced tillage by introducing a 2-wheel tractors, which use a shallow rotovator variety by a six-row seeding machine to prepare the soil and plant seed in one operation. In India a four-wheel version saves time by tilling only the strip of land where the seed is planted - rather than the whole land surface. In north-western India and Pakistan, a tractor pulled seed and fertilizer drill allows farmers to place seed directly into the standing rice stubbles without any ploughing.

Application of Conservation Agriculture/Zero tillage is the concept of optimizing yields and profits while ensuring provision of local and global environmental benefits and services. Zero tillage along with other soil conservation practices is the corner stone of CA. About 47 percent of the 95 million hectares' of Zero tillage is practiced in South America, 9 percent in Australia and 3.9 percent in Europe, Asia and Africa.

According to the principles of Conservation Agriculture, the soil is a living body essential to sustain quality of life on the planet. Zero tillage is the mainstay of CA. Zero tillage is planning of crops with minimum soil disturbance. In this system seed is directly placed into a narrow 3-4 cm wide and 4-7 cm deep slits made with a drill fitted with chisel or inverted T type openers without prior land preparation. This biological tillage replaces mechanical tillage. Presence of residues on the soil surface helps conserving soil moisture and also serves as a source of energy for soil macro and micro fauna for bio tillage.

If the crop is planted timely and seed and fertilizer inputs are placed at an appropriate soil moisture contents and at the appropriate planting time, there is no reason why yield of wheat, rice, fodder, oil seed and pulse crops should be low. All the available results suggest that timely planting with 'Zero till-seed-fertilizer drill improves the input use efficiency and saves about Rs.2200-3000/ha by planting wheat with Zero till drill.

Normally a trained tractor operator can plant one acre in an hour. Farmers can easily plant 4-5 hectares wheat per day in 8 hours with Zero tillage drill. It facilitates timely planting of crops. Why should we shift to Zero tillage system? What are its advantages? Traditionally farmers sow wheat after rice after tilling their field 6-8 times with disc, harrow and cultivator following by 2-3 plankings. This increases the cost of production, delays wheat planting and also results in loss of residual soil and moisture after the harvest of rice, which can be used with advantage for the subsequent wheat crop. Zero tillage saves time in planting, saves fuel, water, improves efficiency of phosphatic fertilizers, reduces wear and tear of tractor, promotes residue management and helps reduce air pollution. It is observed that Zero tillage increases farmer's profit by Rs.2500-3000/ha.

Zero tillage system can be used in all types of soils except excessively wet and compaeted soils. Fields having weed problems would need tillage for mechanical weed control or using chemicals before planting the crop with Zero tillage may.control them.

For good results it is necessary that fields be properly leveled, kept weed free, for efficient soil moisture at planting time and the drill is properly calibrated and maintained.