By- C.S.Shabong & Ian Saiborne
Fig. 1 - A view of a Soil Testing Laboratory
Soil is a natural medium for plant growth. In addition to anchoring the plant, soil also acts as a reservoir for plant nutrients. There are sixteen elements considered as essential for plants by scientists, viz., Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulphur, Iron, Manganese, Zinc, Boron, Copper, Molybdenum and Chlorine. These elements are considered essential because, in their absence or deficiency, the plant will not be able to flourish and complete its life cycle. All the essential plant nutrients except carbon, hydrogen and oxygen are absorbed by the plant roots from the soil.
Soil is a complex matter made of three basic components i.e., soil solids (both mineral and organic origin), soil water and soil air. Different soils differ in their physical and chemical properties as well as the life forms flourishing in it. These components are the results of various factors ranging from climate, organisms, parent materials and age of the soil. This complex natural property of soil governs how the plant nutrients are available to plant roots. In some situations, a particular nutrient is available in plenty, where as others are locked within the different soil constituents making them unavailable to plant roots.
The soils of Meghalaya are dominated by the laterite group. The hilly soils are mostly derived from gneissic complex parent materials and the plains adjacent to the south and northwestern plateaus have alluvial origin. The soils are fairly deep to very deep and ranging from light to medium sandy loam to clay loam in texture. They are also generally characterized by low cation exchange capacity and low base saturation percentage. Because of their location in humid areas the soils are subjected to strong leaching of cations and other elements from the surface resulting in accumulation of clay and Iron(Fe), Alluminium(Al) oxides in the sub-surface horizons, which impart red and reddish brown color to these soils. The soils are also strongly acidic to mild acidic in reaction with pH readings ranging 4.5 to 6.0.
The soils of Meghalaya are of moderate fertility, having high organic matter content, which is an important indicator of the nitrogen supplying power of the soils. However they are generally low in available phosphorus with medium to high ratings in available potassium status. The soils favor growing of a wide variety of forest trees, plantation crops and orchards like arecanut, cashewnut, tea, pineapple, citrus, black pepper and banana etc. If external source of nutrients are supplemented in the form of fertilizers or organic manure, these soils can support a continuous cultivation of cereals and field crops viz., rice, maize, millets, pulses, potato and different types of vegetables.
The Department of Agriculture has established Soil Testing Laboratory in 3 districts of the State viz. Shillong, Tura and Jowai. These laboratories provide free soil testing services to the farming community where soil samples are routinely analyzed for their different physical and chemical properties including their health and fertility status. Generally soil samples are drawn from arable lands by following certain laid down procedures, before being processed and tested. The results from these different tests are then interpreted, correlated with the soil capacity to support sustained crop production, and whether external inputs like fertilizers are required to be added to the soil. Soil testing is a pre-requisite for moving towards maximizing agriculture productivity and optimizing the use of precious inputs for better margins to the cultivator or farmers. The soil testing laboratory, apart from providing free soil testing service to farmers also issue them a Soil Health Card, a two page document which provides an overview of the laboratory soil test results, as well as a crop and fertilizer dose recommendation.
Fig. 2 - Online Soil Health Card Application
This soil health card is a document which evaluates the health or quality of a soil as a function of its characteristics, water, plant and other biological properties. The card is a tool to help the farmer to monitor and improve soil health based on their own field experience and working knowledge of their soils. Regular use will allow them to record long term trends in soil health and to assess the effects of different soil management practices. This card is most effective when filled out consistently by the same person over time. It provides a qualitative assessment of soil health. The purpose is not to compare one soil type against another, but rather to use indicators that assess each soil’s ability to support crop production within its capabilities and site limitations.
As part of its e-governance initiatives under the Meghalaya AGRISNET project, whose vision is to provide improved services to the farming community; the Department has successfully implemented a pilot project, online soil health card in East Khasi Hills district. Developed and customized for Meghalaya by NIC, West Bengal, the online soil health card uses web services to process all the input data as well as deliver the final e-soil health card via the internet. The application also sends an automatic SMS message to the farmer’s mobile phone at the time of registration of soil sample and when the soil health card is ready for generation at the user level. The first SMS informs the farmer about his SHC registration number while the second SMS informs that the SHC is ready for generation by the user. The online SHC is expected to provide a service level of 15 days or less as compared to more than 30 days in the earlier manual system. Further, if the farmers send properly dried soil sample, the service levels will come down even to less than 7 days. Presently, the SHC can be generated both in English and Khasi language from any Common Service Centre (CSC) or any kiosk with internet connectivity. Work on a Garo version will also be taken up shortly.
(The Writers are working as Agriculture Development Officer (info) and Scientific Officer (Soil Survey) respectively in the Directorate of Agriculture, Meghalaya)