Throughout India, only spring wheats are grown, although they are raised in winter.
In the southern hills of Tamil Nadu, two crops of wheat are raised in a year. The first crop is taken between October-April and the second crop in May-September.
The annual rainfall in all the wheat growing zones ranges from 12.5 to 100 cm. But most of this rain is received in summer or during the monsoon. In winter when the wheat is in the field, the rainfall ranges anywhere between 3 and 7 cm. To get good yield irrigation is essential and this enables the farmer to provide the necessary inputs. Irrigation facilities range very widely in different states. In Punjab, about 85 per cent of the wheat crop receives irrigation, whereas in states, like Maharashtra, Karantaka, Madhya Pradesh, only 13-25 per cent of the wheat area is irrigated. The high temperatures on both ends of the wheat season restrict the cultivation of this crop in India to the cooler months. High temperatures in September do not permit good tillering of the crop. They are also favourable to root rot and seedling blight fungi. The hot summer during the grain ripening period hastens the maturity of the crop.
Before the ‘Wheat Revolution’,different wheat varieties were grown in each of the zones based on their maturity periods.
But with the availability of photo-insensitive varieties in recent years, the same varieties could be grown from the high Himalayas to Cape Comorin.
Wheat cultivation has spread to the rice growing areas of eastern India in recent years in a big way. However, the pre monsoon showers towards the end of March force the harvesting of the wheat crop by the third week of this month.
SOILS. Well drained loams and clayey loams are considered to be good for wheat. However, good crops of wheat are raised in sandy loams and the black soils also. In the past, it was considered that durum wheats were more suitable for cultivation in black soils than the aestivums. But this is not true with the present day aestivum wheats which are grown in all types of soils in the country.
ROTATION. Normally, the rabi, wheat is followed in kharif by crops, such as maize, jowar, bajra, cotton, and arhar. Sometimes, some of the green-manure crops such as sanai, moog, guar, lobia or hubam clover, are sown immediately after kharif to enrich the soil. Gram,linseed,barley and mustard are also included in rotations. With the recent emphasis on intensive agriculture the rotation patterns have undergone some changes. In Punjab, Haryana and western U.P., rice has become an important crop in the kharif. It is followed by wheat. In eastern India ,wheat has become an important crop and is grown extensively after rice on land which is left either fallow or put under boro rice. In some states like West Bengal, the rice wheat jute rotation has become common. The sugarcane wheat rotation is also common in northern India. Where irrigation is available and legume crop is grown in between two serial crops to enrich the soil as well as to get the needed pulses.
In the black soils of central and peninsular India, unirrigated wheat is rotated with jowar , bajra or cotton in kharif in the preceding year. The growing of quick maturing crops such as mung, gingelly, onion, coriander and even groundnut or early sown maize such as catch crops before wheat are fairly common. The irrigated wheat rotated with variety of garden crops and irrigated rice, rabi jowar, ragi (Eleusine coracana) etc.
All over India, the growing of wheat mixed with barley, mustard, gram lentil and safflower is quiet common, A row of mustard or safflower for every 8-12 rows of wheat is put. This mixed cropping meets the family requirement for cereals, pulses and oil and also gives some insurance against pests, diseases and other natural calamities which may destroy the single corp. north western India and in tarai areas of U.P., wheat is grown as companion crop with row crops e.g.- sugarcane. About 3-4 tonnes of wheat is harvested as bonus in such companion cropping, without affecting the yield or quality of sugarcane.