Soil and Water Conservation

Vol.04 Issue No. 04
July - December, 2002

Soil Sampling for applying Discriminatory Fertilizer For Rubber

Soil Sampling is the most important operation in a Soil Testing Programme. In most cases, the validity of the conclusions based on Soil analysis is closely related to the quality of the samples analyses. The method of samplings depends on the purpose for which the samples are drawn. For fundamental studies of soils, samples are drawn on profile basis. In investigation of the productive capacity of soils, samplings can be confined to the surface layer. Sub Soil samples are required only for special purposes like diagnosis of unusual problems.

Soil sampling for offering discriminatory fertilizer recommendation for rubber: Soil samples are collected in the form of composites samples (comprising ten random pits) taken at two depths viz. 0-30 cms and 30-60 cms. The intensity of sampling is in the order of one composite sample for the order of one composite sample for every 20 hectares. The most satisfactory method of taking samples is to walk across the field two or three times in a zig zag pattern and to take pits along this direction. The soil samples taken from the random pits (at two different depths) are placed on a sheet of paper; mixed well and divided into four sections. Two opposite quarters are discarded. The other two quarters are mixed again place back on sheet and quarter again. This is repeated until the volume of Soil has been reduced to that required. For characterizing inherent soil properties, collection is made from inter rows, since soils in the inter rows are less disturbed than that in the tree rows. For characterization of soil properties influenced markedly by management factor, collection of soil sample is made from the tree rows. Where composite samples are taken, a detailed History of the agronomic practices; manurial application etc. should be recorded.


Quantity of Finely Ground Lime Stone Required to be Raise the Ph Value of Ploughed Layer

(0-7" or 0-18 cms)

Of the Soil From The Value Indicated To A Ph. 6.5

Soil Region & Texture

Quantity of Lime Stone (Tons/Acre)

From Ph 4.0 to 6.5 From Ph 5.0 to 6.5 From Ph 5.5 to 6.5
A. Warm Humid
* Sand and Loamy Sands 1 ½
* Sandly Loamy - 2 1
* Loams and Silt Loams - 2
* Clay Loams - 5 3
B. Cool Temperate Hills
* Sand and Loamy Sands 3 2 1
* Sandy Loams - 3 2
* Loams and Silt Loams - 2
* Clay loams - 6
C. Valley Soils
Organic Water Logged 9 7

This is rough Calculation. Liming need to be done after Soil Test as per recommendation. Liming material should be evenly broadcast and worked into the soil at least a month before sowing, to allow time for completing the reaction, keeping the land moist, hastens in the base exchange process. It is also believed that liming once in five years serves the purpose but the Ph Value of the treated soil should be carefully watched so that if it falls to a harmful level, second application may be given.


Different Category of Farmers

A. Small Farmers : Cultivators with land holding below 5 (five) acres. In case of Class I. irrigated land as defined in land Ceiling Legislation; the Ceiling will be 2.5 acres.

B. Marginal Farmers : Cultivator having land holding upto 2.5 acres. In case of Class I. Irrigated land as defined in the Land Ceiling Legislation; the Ceiling will be 1.25 acres.

C. Agricultural Labourers : Cultivators without any land holding but having a homestead and deriving more than 50% of their income as Agricultural wages.

Soil & Water Conservation Meghalaya Newsletter. Vol. 4 (4) July - December, 2002