AGRICULTURE AND IRRIGATION

SOILS

The soils of the district are formed from the Deccan trap which is the predominating rock formation of this district with small out-crops of laterite at a few places in the Poladpur taluka and in the Matheran hills. Various types of these soils are marked out as per topographical situation and location. They ' are generally grouped as forest, varkas, rice, khar or salt, coastal alluvial and laterite soils.

Forest soils.

These soils are not used for agricultural purposes but yield valuable forest products such as teak-wood, hirda (myrobalan), beheda, pepper, etc. However, these soils are heavily eroded due to grazing and cutting of the forest trees.

Varkas soils.

These soils are located just below the forest soils all along the steeper slopes. They are shallow in depth, which varies only between a foot and a foot and a half, heavily eroded and sandy in texture and yellowish red to yellowish grey in colour with acidic reaction. They are poor in organic matter and nitrogen and possess very little retentivity of moisture. They yield kharif millets but the production thereof could be increased with the addition of bulky manures, lime and nitrogenous and phosphatic fertilisers.

Rice soils.

The district is the second largest producer of rice in the Maharashtra State. The region is peculiarly terraced and, though the small strips in between the two terraces are levelled, it is difficult to get even a few gunthas of land in one piece in a levelled condition. The depth varies between two and six feet. They are loamy in texture, yellowish or reddish grey in colour, neutral in reaction and almost devoid of lime. They are formed from the trap rock from the Sahyadri ranges under heavy rainfall and humid climatic conditions. The linear response of rice to the application of nitrogenous, phosphatic and potassic fertilisers is observed in these soils. Addition of bulky manures in these soils is also found to be advantageous from the point of view of yield. There are some patches of manat soils in Mangaon taluka which are rich in clay and silt and which become stiff and hard when dry.

Khar soils.

These soils are situated on the flat, levelled land near the sea at the point of creeks formed due to the rivers. They are flat clay to clay loam in texture and reddish or yellowish grey in colour. These soils contain hardly more than one per cent of soluble salts. These soils are formed due to the deposition of salts by the sea or from lands reclaimed from the sea. Large tracts of land are going out of cultivation due to the ingress of the sea and, in order to reclaim these lands, the Government have formed the Khar Land Development Board which has undertaken ambitious projects of the reclamation of khar lands.

Coastal alluvium soils.

These soils are found all along the coast and at places where there are no creeks. They are deep soils developed on flat land and loamy in texture with reddish grey colour. They are devoid of clay fraction or humus and are open in nature. The profile is difficult to differentiate and is excessively drained. Calcium carbonate is found in abundance throughout the profile but calcium has not entered the clay complex. The sub-soil water level is only from ten to fifteen feet deep. The salt contents of the well water are higher in the proximity of the sea; but due to excellent drainage, its use has not produced any deleterious effects. The soils are almost neutral or slightly on the alkaline side of neutrality. Good garden crops like coconut, areca-nut, plantain, etc., are grown in these soils, depending upon the availability of water.

Laterite soils.

Out-crops of laterite rock are observed amongst the Sahyadri ranges amidst the trap rock mainly at Matheran and in the Poladpur taluka. These soils mostly occur on the mountain peaks. They are coarser in texture, wherever there are no forests. They are yellowish-red in colour and shallow in depth and yield coarse millets and niger. The heavy rains in the mountainous regions thoroughly leach the soils turning them acidic in reaction and devoid of calcium carbonate. They are rich in sesquioxides, the ratio of silica to sesquioxides being less than two. But they are generally poor in exchangeable bases or in fertility constituents. However, the soils from the forest region are well-supplied with nitrogen and organic matter. The general analysis of the typical soils of the district is given in the table below:—

TABLE No. 9

CHEMICAL ANALYSIS OF SOILS.

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