Prof. (Dr) R.D. Gupta
Agriculture of India has now entered in a post Green Revolution stage. It is quite evident from the growing concern about the sustainability of the rice wheat cropping system as the growth rates of rice and wheat yields have either become stagnant or declined. This is more so in rice-wheat growing states like Punjab, Haryana, eastern Uttar Pradesh, Madhya Pradesh, Bihar, Himachal Pradesh and Jammu and Kashmir as well as in few southern and eastern states of the Country (Mahajan and Gupta, 2009). It is attributed to imbalanced use of chemical fertilizers which resulted in the deterioration of physical, chemical and biological properties of the rice-wheat growing soils. Further, it is added that excessive use of pesticides created new pests which caused a great loss to the rice and wheat crops. Thus, demands for agricultural technology are changing and diversitying. These demands can be broadly categorized into following categories:-
i) Technologies to break the stagnation of yied growth in intensive irrigated agriculture.
ii) Technologies for dryland farming which account for two thirds of India’s cultivated land.
iii) Technologies for diversified farming systems in high value commercial crops.
iv) Technologies for more sustainable use of natural resources.
The present agricultural technologies however, relate with the first category i.e. how to break the stagnated or reduced yield of rice and wheat grown under irrigated conditions.
Balanced use of fertilisers: Always apply fertilizers on the basis of soil test reports. Soil test should be done twice in a year i.e; prior to sowing Kharif and Rabi crops. Soil samples are taken up to a depth 25 cm and should be sent to the nearby soil testing labortaries under State Department of Agriculture. Strictly follow the recommended doses of chemical fertilisers. In the absence of soil testing report apply fertilizers to crops (rice and wheat) based on “Package of Practices” formulated by the State Agriculture Universities or Departments of Agriculture.
Use of secondary and micronutrients: Where the worthy farmers are growing rice-wheat crop rotation for years together, there is a lot of soil sickness. The soils have become hungry for secondary (Ca, Mg, S) and micronutrients (Zn, Cu, Mn, Fe etc) also besides N,P and K. Take care of these nutrients also in consultation with official/officers of Department of agriculture depending up on their status in the soils.
Use of organic manures including green manure: Application of well decomposed organic manures like farm yard manure, compost, was usually neglected by a large number of farmers with the advent of Green Revolution. Addition of organic manures must be revived. Organic manures besides having primary and secondary nutrients also contain micronutrients as well as growth stimulkating and growth regulating substances. Organic manures improve physical, chemical and biological properties of the soils.
Growing legume as green manure for improving the growing crop’s yield and quality of soil is one of the oldest practices. It proves more beneficial particularly for light soils. The main influence of green manuring is to augment the supply of nitrogen and other nutrients. The other benefits are protection of soil from erosion and prevention of nutrient’s loss by leaching.
Growing of legumes: Legumes are known as soil builders. It is because they are capable of fixing atmospheric nitrogen in their nodules and from there, this fixed nitrogen enters into the soil through osmoses process. Thus, they play an important role in the maintenance of soil fertility. They can be grown either as rotation of the crop or as inter crops with cereals and oil seeds to cut down the in organic nitrogen requirement of non-leguminous crops.
The quantity of atmospheric nitrogen fixed by Rhizobia depends up on the kind of the legume, the strain of Rhizobium, nature of the soil and the supply of other nutrients to the crop necessary for their optimum growth. The amount of nitrogen fixed varies with the kind of leguminous crop. Good legumes like alfalfa and clover may fix more than 100 kg per hectare per year, though even more than this figure i.e; 188-260 kg per hectare per year, has been found for alfalfa under New York conditions. In case of peas and beans its figure may be between 40-50 kg per hectare per year.
Growing of pulses: Pulses being leguminous crops are also required to grow. It is because, India is the only country which consumes huge quantity of pulses as it is perhaps the major source of cheap protein particularly for vegetarian. Hence, the farmers are required to provide more incentive by the Government to grow more pulses by way of importing more minimum support price. In rice-wheat cropping sequence, the farmers can either grow summer moong or gram instead of wheat at least once after three years.
Adoption of right kind of crop rotation: On irrigated lands intensive cultivation results from following rotations of higher intensity which ensure the raising of large number of crops in a short period. The below mentioned rotations are the typical examples of in this respect:-
1) Green manure (Dhaincha) – rice – wheat
2) Green manure (Dhaincha) – rice – berseem
3) Green manure (Dhaincha) – rice – gram
4) Green manure (Dhaincha) – rice – lentils
5) Green manure (Guar or moth) – maize – wheat
6) Green manure (Sanhemp) – wheat
Promote diversifying agriculture: Promotion of nich products such as traditional rice and basmati varieties, organic farming, livestock rearing and dairy rearing and farming, proliferation of poultry and fish farming are the present needs of the farming to promote.
Proper interculture or tillage: Proper interculture in the cultivated crops, consists of giving shallow cultivations by way of hoeing. Generally all crops respond to hoeing in the growing stage. But in some cases hoeings are as essential as preparatory tillage. Maize, wheat and sugarcane for example respond very much to hoeings. There are a number of benefits of interculture. Firstly, the surface soil gets loose and free air begins to circulate. Secondly, the soil moisture below the surface soil is conserved and becomes available to the plants for their growth. Thirdly the root system of the crops develops fully and freely so that the crop grows vigorously. Fourthly, the weeds growing in the soil and robbing of the crop of its plant food are up rooted and destroyed.
Use of mulch: Mulching consists of either stirring the upper surface up to a depth of 2-3 cm or spreading litter, plant leaves and crop residues on the soil with the object to conserve the soil moisture and reduce its loss through evaporation. The main benefits that accrue from mulches are: Protection of soil from blowing and washing away by wind and water erosion, significant reduction in run off loss and utilization of moisture advantageously for sowing of crops. During the summer months mulching helps in keeping lower depths of soil cool, which is an important condition for the growth of tender plants. Mulch prevents the formation of cracks appearing in the soil, which lead to the formation of clods and, thus, reduces the cost of tillage operation under such situation. Apart from this mulching has been found to increase the productivity of wheat and maize and rice grown under upland conditions.