Agriculture for Engineers 4 (3+1)

Lesson 33. Soil Requirement for Fruits, Vegetables and Flowers Crops

33.1 SOIL REQUIREMENT

Soil is a thin outer covering of the earth, directly developed by natural forces acting on natural materials. It is a basic medium for plant growth, supplies nutrients for growing plants. Soil is the home of the plant root and the reservoir for essential nutrients and water for its growth and development.

33.1.1 Types of Soil

On the basis of pH, EC and presence of ESP the soil are grouped as (1) Saline (2) Alkaline (3) Saline-alkali (4) Acidic

On the basis of sand, silt, and clay soils are grouped (classes).

a) Sandy

b) Sandy loam

c) Loamy

d) Silt

e) Silt loam

f) Sandy clay loam

g) Clay loam

h) Sandy clay

i) Clay etc.

Porous aerated and deep soil should be preferred for fruit cultivation. The ideal orchard soil should be at least 1.8 m deep having a uniform texture, well drained, non-saline and fertile. Soils with a poor sub soil stratum should be avoided. Fruit tree will not grow well if there is solid rock or permanent water close to the surface of the soil. Sub soil with a hardpan or pebbles within 120 cm of the surface soil should not be chose. Extreme conditions of top and sub soil namely very heavy (clayey) and very light (highly sandy) should be avoided. Heavy soils are difficult to handle on account of poor drainage while very light soils are infertile because of leaching of nutrients. Medium textured silt loam or fine sandy loam makes good orchard soil.

Most fruit plants like slightly acidic to neutral soil reaction (pH 6-7). Some fruit species can some times tolerate little more acidic or alkaline medium but too acidic or too alkaline soil should be avoided.

Soils with fluctuating water table are not suitable because the water table moves up and reaches the root zone damaging the root hairs. When the water table goes down, the trees with shallow root system struggle for moisture and nutrients causing reduction in growth and vigour of trees. Thus soils having water table depth of less than 3 m are not usually preferred for establishing an orchard. Some fruits, however, such as, Mango, Grape, Lime, Ber, Custard Apple, Avocado and Cashew do well on for wide range of soil type.

33.2 SOILS AND WATER MANAGEMENT IN RELATION TO

HORTICULTURAL CROPS

After laying out the orchard, planting of the fruit trees the farmer is interested in optimum growth of trees and maximum production of fruit. Soil management, cultivation of inter crop, irrigation and manuring are the factors to be considered for getting economic return from it, and maintain the health of trees.

33.2.1 Soil Management

Soil management practices such as cultivation, (interculture, weeding), mulching, sod culture etc. are of various system used in different parts of the country.

(a) Cultivation (Clean Cultivation):

Cultivation of orchard soil is important terms, incorporate fertilizers and green manure and to facilitate absorption of water in the soil and also increased the biological activities of soil due to better aeration. Deep tillage is not important in orchards because it may cause injury to the roots of the trees.

(b) Mulching:

It is the system in which materials like hay, straw, cut grasses or plastic sheet spread over soil surface mulching preventing evaporation of water from soil and it also improve structure and aeration by reducing rain drop impact.

Fig 1. Mulching

(c)  Sod culture:

This is system in which fruit trees are grown in any tillage or mulching. The grass may remain without cutting but it is usually cut one in a year. This system is not followed in tropical and subtropical region where it is applied in temperate region.

Fig 2. Sod culture

(d) Weeding:

There should be the removal of weeds, so, as to facilitate other operation like irrigation, manuring etc.

(e)  Inter cropping:

The crop which are raised in the orchard for increasing the income from land are considered as intercrops e.g. vegetables, pulses, short duration fruit crops banana, papaya, pineapple, phalsa etc., can be grown in the orchard.

Fig 3. Inter cropping

1) These fruit trees, which are used as intercrops are also known as filler crop.

2) Cover crop: The crops grown to cover the soil to protect it from soil erosion e.g. grasses, pulses, moong, cowpea, peas.

3) Green manuring crops: The crops grown in the orchards and after certain growth, they are buried in the soil for addition of organic manure e.g. sunhemp, cowpea etc.

(f)   Manuring:

Fruit trees take large amount of nutrients from soil for their growth. So far maintaining fertility of soil in orchards, manures and fertilizers are added in the soil.

(1) Organic manures: Compost, FYM, oil cakes etc., improve the physical condition of soil and add some nutrients.

(2) Fertilizers: Among chemical fertilizers urea, ammonium sulphate, super phosphate, D.A.P. are common.

Application of fertilizers is depend on the soil and climatic conditions and kind and age of crops.