No crop can be grown without being adequately supplied with the requisite amount of water at the proper time. A thorough knowledge of the hydrological cycle, amount and distribution of rainfall, water resources and irrigation projects in India facilitates efficient utilization of water for crop production. Inadequate supply of water to crops in semi-arid and arid regions adversely affects agricultural production.
Properties of water, the mode of its entry into the soil and its absorption by roots of crops are important for irrigation. This necessitates accurate determination of the soil moisture content, the plants and available water which is essential for growth and yield of crops. Its deficiency adversely affects their growth and yield. Irrigation must be extended to unirrigated areas in order to increase the production of food, fibre and fodder for which we must know the source of irrigation water, units and methods of measurement of water, methods of irrigating crop fields, factors affecting the choice of irrigation methods, the degree of the suitability of the available water for irrigating crops and the factors affecting the suitability of water for irrigation. As water is a relatively scarce commodity, we must know whether water of a little inferior quality can be utilized to irrigate crops. In addition, we must be familiar with the precautions which need to be taken in this regard.
The accumulation of excess water in the soils of the crop fields affects the growth of crops adversely enough to reduce their yields. Choice of the method of land drainage varies with the variation in the topography of the land. It is also necessary to rectify the causes of waterlogging to bring the waterlogged land back under the plough to increase agricultural production. This necessitates drainage investigation and laying out of the proper drainage system.
Water requirement of crops depends on the climate and the crop. More water is required to produce crops in the arid region than in the humid region. Crops like paddy and sugar cane require much larger amount of water than finger millet and pearl millet.
The book extensively deals with all these aspects related to soil and crop production and suggests measures to enhance productivity through water conservation and proper management of water resources. It will be highly useful for the students, teachers and researchers working in this field. Besides, agriculturists and general readers will also find it useful and informative.
A.K. Kolay, M.Sc. (Agriculture), Ph.D., is a retired professor from the School of Agricultural Science & Rural Development, North Eastern Hill University, Shillong. During his long academic career he served at the Soil Conservation Department of the Government of Himachal Pradesh and also at the National Bureau of Soil Survey and Land Use Planning, New Delhi. He has to his credit several books on Agriculture and Bio-Science which include: Manures and Fertilizers and Soil Genesis, Classification, Survey and Evaluation.
