Tremendous increase in crops yield in the backdrop of green revolution in the 60s went well at least for a few decades. But after the lapse of a considerable period, these are either on decline or remain stagnant.

Decrease in the yields of three major crops wheat, rice and cotton by 73kg, 80kg and 70kg per hectare, respectively in 2003-04 compared with their levels in 1999-00 is an ample proof of the fact.

Crops, major and minor constitute an important sub-sector of agriculture. Their contribution - the agricultural gross domestic product (GDP) - is around 60 per cent. Crops are grown in three well-defined zones in the country.

These are irrigated low lands, rain-fed low lands and mountain areas. More than half of the cropped area is devoted to cereals, one fifth to cash crops and the rest to fodder, pulses, vegetables and fruits.

Wheat is an important cereal crop. It is a major staple food crop of the country. But during most of the years of its history, the country has imported wheat to meet the food demands of its nationals. Similarly, import bill of edible oil is also in billions.

There is a long list of factors that can be attributed to low farm production. Seed is the most vital agricultural input. Certified/approved seed has the potential to increase yield by 20 per cent. Purity, health, vigour and high germination percentage are the desirable characteristics associated with certified seed.

The supply of certified seed is extremely less than the actual requirements of the major crops. Resultantly, about 55 per cent to 92 per cent seed sown in the country is uncertified.

Adulteration of seed by the local dealers and selling the seed of prematurely released varieties by the cotton breeders under the pretext that these are high yielding and disease resistant has caused plausible yield losses. Cotton yield has become stagnant at around 10 million bales.

Water availability for irrigation at critical crop growth stages has significant impact on yield. But the country is facing an acute water shortage. Though the country has one of the largest canal irrigation systems in the world, yet it is overcome water shortage.

Huge water losses in the form of seepage and percolation from the major/minor canals and watercourses during conveyance and distribution have curtailed water use efficiency to a considerable level.

The need is to plug these losses in an attempt to save water for irrigation. All the four provinces have no water for crop sowing in the Rabi season. The limited storage capacity of the existing reservoirs that is on decline due to sedimentation has contributed to this drought-like situation. There is a need to build new dams to store extra water during monsoon season. This water can be effectively used for irrigating the Rabi crops.

Low organic matter, harvesting of exhaustive crops year after year, high temperature, low-rainfall, high-cost and imbalanced use of fertilizers are the factors that cause depletion of cultivated soils.

Application of fertilizers in a balanced amount with standard methods and at appropriate time keeping in mind the soil nutrient status, soil moisture, crop type and crop growth stage can increase yield by 25-75 per cent.

The fertilizers off-take has increased from 3100 nutrient tons (NT) in 1960-61 to 3,020,000 NT in 2002-03. However, the application of fertilizers is not balanced. The best approach is to apply nitrogen, phosphorous, sulphur and micronutrients in order to maximize the yields.

Price of different fertilizers is not in reach of specially, the small farmers. For instance, the price of a 50kg bag of a urea went up from Rs25 in 1960 to Rs460 in the current season.

Whereas, the price of DAP increased from Rs28 per bag to Rs1085 in the on-going wheat season. As a result, the small and subsistent farmers holding 63 per cent of the total farms are unable to apply the recommended dose resulting in low yields per unit cultivated area.

Insects, pests, disease and weeds cause yield reduction up to 20 per cent or more during pre and post-harvest periods. The farmers are bound to use pesticides in order to keep the population of insects and pests under control. The application of pesticides increased from 665 tons in 1990 to 78,133 tons in 2003-04 with an increase in value from Rs39 million to Rs8138 million.

In cotton crop, the use of pesticides is no more effective in controlling pests and diseases on 85 per cent of the area despite massive use of pesticides. Lack of quality control, high cost, adulteration, timely unavailability, and lack of education and the use of faulty equipments by untrained labour are the major constraints responsible for the ineffectiveness of pesticides.

Preparation of fine seedbed is a pre-requisite for optimum seed germination. But the non-availability of necessary machinery at proper time is a major hurdle. The process of mechanization is very slow in the country due to high cost of tractors, seed drills, sprayers, threshers and harvesters. The small farmers have no capacity to purchase them.

Delayed sowing in rice-wheat and cotton-wheat cropping system is described as major yield reducing factor. Research on introduction of early maturing rice and cotton varieties is essential to avoid delay sowing of wheat crop.