THE PLOUGH was thought to be essential tool on the farm in 3000 BC rather even long before. But now with the introduction of modern techniques of sowing and harvesting, use of insecticides, pesticides, rodenticides and improved varieties of seeds, it is no more essential tool as it was before.

The ‘science and art’ of crop production, grazing and range management involves a complex of factors inherent in climate, soil, plant and harvesting. Needless to say that zero tillage is already widely practised successfully in many countries of the world including New Zealand and Australia, which are the largest exporters of food of animal origin which are of high biological values. They had developed this industry from inherently inferior soil. These countries are known for being most efficient producers in terms of per acre of land, labour unit and unit of capital.

Keeping in view the above mentioned factors, projects were planned at the Arid Zone Research Institute, Quetta to grow fodder and other cash crops under ‘zero tillage’ targeting the following benefits.

* Lessen labour costs;

* Grow fodder and other crops with little or no inputs;

* Increase livestock productivity and better cash return;

* Improve fertility of the soil through vegetative rotations;

* Integrate livestock and crop production as separate development of the these two systems is rather dangerous;

* Conserve the farm-grown fodder as silage or hay to cater the livestock needs during the lean periods;

* To assess the validity of this assertion that livestock feed and other crops can be grown successfully under zero tillage.

Research: While comparing various of types direct drills, a leading scientist Howe (1972) emphasized upon their importance and stated that the progress is much rapid. However, with the techniques becoming accepted by the growers for wide range of crops. For example, the 100,00 acres drilled in 1972 included 35,000 acres of autumn sown cereals, 12,000 acres of grasses and about 3,000 acres of other crops namely peas, oilseed, rapeseed and beans. The development of direct drilling in the UK increased from 16,000 acres in 1968 to 1.00,000 acres in 1972. He further mentioned that more and more farmers are adopting minimal cultivation.

The author is of the view that the tilling of land in Potohar and water shed areas of Mangla, Tarbela and other such dams is common when summer crops have been harvested and winter crops are yet to be sown on such lands. The tilled soil is open for erosion, particularly during monsoon. In this connection, Britain’s policy concerning land use is a feasible indicator.

The US Department of Agriculture has estimated that by the year 2010 AD, more than 90 per cent of the area under crops will be grown with reduced tilling system and that some form of no-tillage farming will be used on half of the crop land. Successful efforts to increase the reliability of seedling emergence by this method (i.e. zero tillage or direct drilling) of growing crops have proved encouraging.

New soil management and weed control techniques, such as the reduced or no tillage systems are becoming widespread in the United States and Europe. For carefully managed fields, production costs have been cut and erosion has been reduced almost to zero in the slops. It has been recorded that the plough, a symbol of American agriculture has been responsible for insolvable losses from wind and water erosion. Through the use of appropriate chemicals for weed control, improved crop productivity is possible without ploughing the land. The plough is gradually being retired. In 1976 in the United States, 2.9 million hectares were planted without any tillage, and on area of over 21 million hectares, tillage was reduced from the conventional level. Reduced tillage is the most significant technology man has developed to control soil erosion, maximize cover on the land and conserve energy, labour, water, soil fertility and organic matter in the main food producing areas of the world. In addition a great share of land in hilly areas can be brought into production or planted with more profitable crops.

The effect of tillage and zero tillage systems on soil aggregates in a silt loam were studied by Hughes and Baker in 1977. Three seedbed systems were compared over the spring summer season on pseudo - gleyed “Tokormaru” silt loam, on two adjacent experimental sites. Experiment I was tilled and left fallow over the winter, while experiment II was left in pasture over winter. Both areas were then prepared and sown with choumoellies seed by one of the following systems.

* Traditional plough/disc/harrow, sown with conventional field drill;

* Rotary - cultivation, sown with conventional field drill;

* Zero tillage (or direct drilling) after herbicide application (Paraquat and Dicamba).

As a result of these treatments, the soil which had been sprayed with the herbicide and direct drilled was significantly more resistant to structural damage than the other two treatments as determined by the sieving under water. The soil structural stability under the rotary cultivated treatment appeared to decrease to a greater extent than with tillage based on ploughing, as the length of time out of pasture increased. Dry sieving of soil samples confirmed in the greatest proportion of soil in the smaller aggregate size fraction (less than 1.7 mm diameter) at all sampling dates. The result suggests that the wider use of zero tillage (or direct drilling) techniques and machinery may result in more desirable soil structure being retained under intensive cropping situations.

Research has proved that benefits from the retention of surface thrash over the inter row ground surface in protecting the soil against erosion, and surface drainage problems by slowing down water run-off and aid in infiltration of water into the soil through preventing surface by rain drop impact.

In the light of experiments conducted under the ecosystem prevailing in Quetta and Peshin districts, dry farmed wheat - barley in rotation are recommended. It is further recommended that countries like Pakistan must have crop production and fodder production under single agricultural system. The author is of the opinion that it is injurious to have two separate systems for Pakistan as is practised in few developed countries.

In the light of the findings of experiments conducted in the Arid Zone Research Institute Quetta, Bahawalpur, D.I. Khan and else where in the world namely the US, the UK, Australia and New Zealand, it has proved beyond any doubt that the zero tillage or direct drilling will have no ill effects on the maximum yield. Rather it will minimize soil degradation through erosion and drainage problems. The zero tillage or direct drilling has considerable potentials. The possibilities of increasing the farmer’s income through biological means are almost remote. The only method left to improve upon, lies in the better management and marketing and lesser input costs.

The new soil management and weed control technologies such as the reduced or no tillage system is becoming gradually popular. For carefully managed fields, production costs have been cut and erosion has been reduced to zero in the slops. It has also been determined that 11 litres of diesel would be enough for one hectare when planted under the direct drilling as compared to 56 litres required under the traditional cultivation methods.

Lesson from the UK land use: In the UK during 1874-1914 change in the use of land took place by the transfer from grain growing to stock raising. During this period area under wheat fell from 3.8 to 1.0 million acres and under permanent grasses increased from 23.7 to 27.4 million acres. During recent years, the area under wheat and barley remained 4 million acres, while under permanent grasses has been over 31 million acres. The mobility of one lakh acres from crops to livestock raising (tilling to zero tillage) each, is taking place every year for last 40 years. The land acreage of Britain is almost equal to Pakistan and Pakistan needs to adopt the same policy in this connection.

Visible benefits: The ill-effect of zero tillage or reduced tillage have not yet been reported from any corner. However, its accrued benefits are as under:

* In an open soil the micro-organism e.g. nitrosomonas helpful in the process termed ‘vitrification’ suffer from sun rays, which can be prevented;

* Nitrogen losses to the atmosphere from an open agricultural soil are comprized of gaseous emission e.g.NH3, N20, NO2 and nitrogen and nitrogen (N2), although incidental losses particulate nitrogenous compounds due to wind erosion do occur in arid climates;

* The relative contribution of wind erosion appears limited and generally leads to fall-out in the vicinity of the source. However, volatilization losses from arid zone arable lands are considered to be significant. This gaseous loss can be greatly prevented by avoiding the conventional tillage to a greater extent;

* The retirement of conventional plough will greatly reduce the erosion of soil in the arid zones due to winds and water;

* The fertility of the soil can be improved through reduced tillage and vegetative rotations;

* The labour costs will be reduced and crops can be grown with little inputs;

* Water saving will amount to 25-35 per cent. The dry areas where the problem of water shortage persists, will be solved to a greater extent.

* Productivity of crops and livestock can be significantly increased;

* The farm grown fodder can be conserved as silage or hay to cater the livestock needs during the lean periods.

Theory negated: The centuries old theory; the more you plough, the better crops you will harvest (dab dab kay wah tay raj raj kay khah), does not hold good any more. It stands negated and disapproved.Today we say, keep your eyes open and stay abreast with the latest scientific findings.