THE average per acre yield of wheat in the country is far less than in other wheat- producing countries. This can be attributed to late sowing of the crop and insufficient irrigation over the required period of time. Indications are that irrigation water is going to be in short supply due to rapidly increasing population and indiscriminate exploitation of the scarce water resources.

Various agricultural inputs like seed, fertiliser and diesel are getting costlier over time. Therefore, there is a dire need to use these inputs efficiently in a sustainable manner. The raised-bed planting of wheat in the crop sequences of soybean, maize or cotton is in keeping with the shortage of water and other inputs.

This system of cultivation is similar to zero tillage in field preparation. The cropping systems other than rice-wheat will be more profitable compared to conventional system of cultivation. A substantial amount of diesel, irrigation water and other agricultural inputs will also be saved. The system is eco-friendly, profitable and more sustainable.

Raised-bed planting of wheat is advantageous in areas where ground water level is receding and herbicide-resistant weeds are creating a problem. Wheat sown with this technique in medium to heavy soils with good moisture has resulted in better yield up to eight per cent. On raised beds, the plants get more exposure to sunlight which is also important for good yield. In this method, the use of natural resources is more efficient than in conventional sowing.

Management of irrigation water is improved and made simpler and efficient. Cultivation under this technology requires 30 per cent less water than in conventional method. On an equal-area basis, irrigation depth of 5cm in bed-planted wheat is sufficient, as compared to 7.5 cm under conventional sowing. The seed rate is also reduced by 40 to 50 per cent.

Fertiliser efficiency is increased because of better placement, including top dressing applications and of retaining basal dose in the beds where plant roots are concentrated. Wheat seed rates are lower but plant stands are better. Better tillering increases panicle/ear length and bolder grains.

Farmers can apply nitrogen and irrigation at grain filling stage to improve protein content without lodging. It is noted that raised-bed planted crop is more resistant to lodging thereby offering an opportunity for the last irrigation at the grain-filling stage. Reduced lodging gives better yield. The bed planting provides an avenue to work at a higher yield level than the present one. Many farmers do not irrigate after heading to avoid lodging, as a result, water can become a limiting factor during grain filling, resulting in lower yields.

Raised-bed planting facilitates irrigation before sowing and thus provides an opportunity for weed control prior to planting. If pre-sowing irrigation is likely to delay planting, bed planted crops can be irrigated immediately after seeding.

An important advantage of this technology is that most harmful weeds between the beds can be controlled mechanically, early in the crop cycle. Weed emergence on the beds is less and the control of weeds on both beds and furrows is possible through inter-culture with tractor which helps for integrated control of weeds. Herbicide dependence is reduced and weeding and roughing between rows are easier. Major weed species affecting wheat, Phalaris minor, is less prolific on dry tops of raised-beds than on the moist soil found under conventional method. Raised-bed cultivation makes it easier to apply herbicides as the person spraying can follow a line.

Rapid drainage of irrigation water from the bed surface saves from negative effects of pounding and associated water-logging. It avoids de-oxygenation of the upper rooting zone for extended periods and allows access to the bed surface for mechanical or hand activities after irrigation. Pre-sowing irrigation followed by weed removal by cultivation on the beds minimises herbicide use. Late irrigations can be applied with less likelihood of lodging.

Because of easy access by machinery with no compacting of the beds, nitrogen can be applied by banding at first node and later. This leads to much more of the applied nitrogen being used in grain production and much less being lost in irrigation water, through leaching, and as vapour, with associated reduction in environmental pollution. With precision seeding and a better environment for seedling growth because of fewer competing weeds and better root oxygenation, lower seed densities can be used down to 25kg/ha from the normal 50 kg/ha. This makes hybrids a cheaper proposition. Because of a better soil environment, seeds can be planted less deep resulting in faster seedling emergence and earlier full ground cover and capture of solar radiation. This is of particular importance in short season crops and in hotter environments.

Overall economic efficiency is increased with the raised-bed system as use of inputs like herbicides, insecticides, fertilisers, water are reduced, without a major penalty in yield. The most significant benefit in multiple cropping systems such as rice-wheat rotation is that turn-around time between crops is short. Theoretically, wheat can be planted the day after the preceding rice crop is harvested using minimum or zero tillage on beds. A marked reduction takes place in occurrence of serious wheat diseases such as powdery mildew with the bed planting crop. This may be the consequence of modest plant canopy microclimatic differences resulting from the change in plant orientation. Raised-bed planting can be used to increase the diversity of different crops such as vegetables, maize, legumes, oilseeds, cotton and sugarcane.

Sowing of sugarcane particularly in wheat fields is delayed due to land preparation after the harvesting of wheat. An easy way to overcome this problem is the intercropping sugarcane and wheat. In this method, wheat is planted on the ridges and cane is planted in furrows. In case of autumn sugarcane it is easy to plant sugarcane in furrow and wheat on beds. Wheat is harvested in April and sugarcane continues to grow. Yield of both wheat and sugarcane are significantly higher.

Raised-bed planting provides an opportunity for natural, controlled traffic when tillage is reduced and every type of implement can be designed to track in the bottom of the furrow. It reduces compaction in the immediate area on the top of the beds where crop is grown. It assists in enhancing lateral water infiltration and forward water advance. In soils that tend towards the development of salinity problems, the use of permanent beds with retention of crop residues on the soil surface is helpful to ameliorate the salt effects by reducing the concentration of salts in surface layers.

Wheat can be planted on preformed beds of any length, 60-90 cm wide by 15 to 30 cm high, with two or four defined planting rows per bed. For planting on raised-beds, a seed rate of 30 kg per acre is sufficient to obtain a yield similar to 40 kg per acre in the conventional method.

The field should be leveled and prepared well before making beds. Beds should be made well in advance and irrigated to encourage germination of weeds before sowing. This is important for the control of weeds mechanically or during the sowing operation. The upper soil layer should not be dry before sowing; otherwise the seed will go deep and affect germination. Crop residues can be left in furrows for stabilisation. Minimum and zero tillage systems can be used more profitably on beds. Special care is needed regarding the depth of seeding. The utility of bed planting for crop seed production and multiplication programs is immense.

For planting wheat on beds, a tractor drawn bed planter is used. The bed planter is mounted at the back of a medium size tractor. In one pass of tractor, the front big lines of planter makes two beds and three furrows and seed drill at back sow three or four rows of wheat and heavy iron bar behind it close the seeded rows and smoothen the beds.