Soil management for achieving goal of sustainable agriculture

Master Soil Fertility, Fertilizers & Nutrient Management – Notes, Case Studies & Practical Insights – with Rahul

Soil management for achieving goal of sustainable agriculture

A. Terracing:

Terracing is the method of modifying land surface for erosion control and water conservation.
Terracing involves construction of embankments or ridge and steps like structure across the slope.
From experiment, it has been found that soil loss is directly proportional to the slope length of power 0.5.
According to this, soil loss is increased with increase in slope length. Thus, terracing reduces erosion by reducing slope length.

Functions of terraces:

I. Intercept surface runoff and convey it to suitable outlet at non-erosive velocity.

ii. Reduce the slope of length by splitting the slope length in different parts.

iii.Traps the splashed soil particles.

B. Strip cropping:

Strip cropping is the practice of growing different crops in alternate strips across the slope such that they serve as vegetative barriers to erosion.
Erosion is limited to row crop strips and the eroded materials is trapped on the erosion
preventing strip planted to grasses or legumes.
It is important that planting be rotated so that the strip planted to row crops this year will be planted to protection effective crops the next year.
For controlling water erosion, the strips are always on the contour but in dry regions strips are placed across to the prevailing wind direction for wind erosion control.
The strip crops reduce the velocity of surface runoff and force them to infiltrate into the soil thereby facilitates to the conservation of rain water.
The strip cropping controls erosion in two ways:

➢ By slowing down of runoff water flows through the close growing strip and

➢ By increasing infiltration rate which reduces total runoff volume.

C. Contour farming:

Contours are lines connecting points of equal elevation on the ground surface.
Contour cultivation is the practice of doing agricultural operations such as planting, tillage and interculture that are performed nearly on the contour of the area applied across the slope.
In low rainfall areas, the objective of contour farming is to conserve the rain water into soil.
While in high rainfall area the prime objective is to reduce soil erosion or soil loss by reducing the runoff velocity.
In some cases, after interculture operations, a ridge and furrow system on the contour develops and offers greater resistance to surface runoff.
Crops like maize, sorghum, pearl millet, which are normally grown in row are ideally suited for contour cultivation.

D. Sediments catching:

This is the commonly practiced method of soil conservation method in which sediment laden runoff water is diverted to the bund lands or terraces.

E. Growing hedge row:

The leguminous trees are grown on the border of cultivated land or on bunds.
The hedge tree adds organic matter to the soil and prevents the loss of nutrients from erosion thus conserving nutrients.

F. Minimum tillage:

This is the practice of preparation of soil with minimum disturbance of soil retaining 15-25 % crop residue cover.
The primary objective of minimum tillage is to provide proper environment for seed to germinate and to increase water intake capacity of soil and thus to control erosion.

G. Cover cropping:

The practice of growing grasses and legumes to cover the ground surface to control erosion from water and wind.
Cover crops are grown as a conservation measure either during the offseason or as ground protection under trees.
The objectives of cover crops are:

✓ To protect the surface of the soil from being splashed with raindrop.

✓ To build up soil organic matter and improve its physical properties.

H. Use of slopping agriculture land technology (SALT):

The cultivation of crops in sloppy land by conserving soil and thus increasing soil fertility is called Sloping Agricultural Land Technology.
The contour lines are drawn on sloppy land with the help of A-frame and double hedge row of Nitrogen fixing trees are grown considering the contour lines as center.
The double hedgerow protects fields from soil erosion and also conserves water.
The nitrogen fixing trees fixes N to the soil.
The crops, vegetables, fodder trees are grown on the area between two hedgerows depending upon the type of SALT model. This area is called cropping alley which has length 4-6 m depending upon the slope.
The distance between one double hedge row may vary from 30-50 cm.
The hedgerow plants are trimmed to maintain 60-80 cm height of the plants.
The trimming of plants adds organic matter to soils and avoid shading effect to the plants grown in alley.

I. Conservation tillage:

Conservation tillage can be defined as any practice that leaves at least 30 per cent cover on the soil surface after planting.
In this, intensity and frequency of tillage is minimized and plant residues remain insitu.
The weed is controlled by using herbicides.
The success of the various conservation tillage systems is highly soil specific and also
dependent on how well weeds, pests and diseases are controlled.