The GEF Small Grants Programme

in Uzbekistan

How to improve soil fertility?

Draganchuk M.I.

About the author:

Draganchuk Mikhail Ivanovich - head of the peasant farm (KFH) "Dragmi" (Crimea, Saki district, Elizavetovo village).

The peasant farm was established in 1991, its activity began from 3 hectares.

Since 2006, the introduction of No-till technology has begun on 367 hectares. Currently, the area of ​​the farm is 1430 hectares, where the No-till technology is widely used. The entire land of the farm is rainfed, with a rainfall of 220-300 mm per year. The farm grows the following crops (the average yield is given in parentheses): winter wheat (22 c / ha), winter barley (24 c / ha), flax (10 c / ha), chickpeas (11 c / ha), sunflower (15 c / ha).

Soil quality deteriorates every year. Humanity exploits the earth in order to obtain the products it needs. The problems of growing agricultural crops are solved by various types of soil cultivation. Unfortunately, mechanical soil cultivation leads to the destruction of soil biota, a decrease in organic matter, destruction of the soil structure and its erosion. And as a result, the soil loses its "health" and becomes less productive.

M. Draganchuk in his field demonstrates the combined (binary) sowing of sunflower with sainfoin. An excellent biomass grows under the sunflower - "food" for the soil.

In order for an agricultural business to be profitable, a farmer has to face a number of problems:

- reduction of labor and time costs;
- lowering the cost of production;
- saving fuel;
- increasing labor productivity;
- reduction of equipment wear;
- reducing the amount of equipment used, etc.

All of these points are extremely important to business efficiency.

However, in the modern agricultural business, the priority is the problem of preserving the main capital of this business - the soil. It is the fertility of our soils that will determine what product we can get from our lands, its quantity and quality. This, in turn, will affect not only the quality of life of farmers, but the whole of society.

Thus, to preserve the soil, you need:

- stop soil erosion (wind and water);
- reduce the density of the soil;
- improve its structure;
- keep more moisture;
- to increase the amount of organic matter in the soil.

How can this be achieved? - Very simple! To do this, the farmer needs:

- stop mechanical tillage;
- plant residues should not be embedded in the soil, but mulched and left on its surface;
- keep all the moisture falling out in the form of precipitation
- to reduce the number of operations in the field, which reduces soil compaction.

The following table will help you understand how each of the above steps can help you solve soil problems.

Soil conservation challenge

Solution

Cause and investigation

Stop soil erosion (wind and water)

Stop mechanical tillage

Plowing and other mechanical processing contribute to the disruption of the soil bond into a single whole, crushing it. This helps the wind blow away soil particles and water wash them away during irrigation and / or rainfall. Every year around the world due to erosion is lost about 24 billion tons of fertile soil. The more we plow, the more soil is blown out and washed away.

Do not embed plant residues into the soil, but mulch and leave on its surface

Coating of plant residues on the soil surface prevents weathering and leaching of the soil, as well as erosion of its fertile layer.

Reduce soil density

Stop mechanical tillage

Mechanical processing does not reduce the density, but rather increases it. Plowing is a means that temporarily relieves symptoms, but does not eliminate the cause of soil compaction - a small amount of organic matter in the soil, loss of soil biota and, as a result, a decrease in the humus content in it.

Do not embed plant residues into the soil, but mulch and leave on its surface

Plant residues are food for the soil. The presence of as much organic matter as possible contributes to the improvement of the soil structure, its decompaction, is food for soil microorganisms that "loosen" the soil.

Reduce the number of operations in the field, which reduces soil compaction

The greater number of vehicles passing through the field contributes to its compaction. It is necessary to reduce to a minimum the passage of machinery over the soil.

Improve soil structure

Растительные остатки не заделывать в почву, а мульчировать и оставлять на ее поверхности

Plant residues are food for the soil. The presence of as much organic matter as possible contributes to the improvement of the soil structure, its decompaction, is food for soil microorganisms that "loosen" the soil. Vertical moisture currents and soil porosity are improved.

Stop mechanical tillage

Mechanical processing crushes the soil and makes it prone to erosion. It disrupts the biological, chemical and physical connections of soil elements with each other. Mechanical treatment raises the soil layers, increases the reaction of the soil with oxygen and thus kills the soil anaerobic biota, i.e. one that lives in soil without the presence of oxygen. Such microorganisms are important for improving soil structure. Their loss leads to a deterioration in the structure of the soil.

Reduce the number of operations in the field, which reduces soil compaction

The greater number of vehicles passing through the field contributes to its compaction and deterioration of the structure. Must be reduced to a minimum the passage of machinery over the soil.

Retain all moisture precipitated

The soil must have optimal moisture content for normal operation. Excessive drying out of the soil and subsequent excessive watering does not contribute to maintaining the optimal level of moisture in the soil. The better the moisture content, the better the performance of microorganisms and therefore the structure of the soil.

Retain more moisture

Stop mechanical tillage

Any soil cultivation operation makes it more vulnerable. The wind carries moisture away from the soil faster, and the sun dries it up.

Do not embed plant residues into the soil, but mulch and leave on its surface

Plant residues on the soil surface prevent moisture loss due to sun and wind. The presence of plant residues helps to retain moisture in the soil, reduce the amount of irrigation required on irrigated lands and get more crops due to the increased soil moisture in rainfed lands.

Increase the amount of organic matter in the soil

Do not embed plant residues into the soil, but mulch and leave on its surface

At present, when growing cotton, up to 1 t / ha of humus are extracted from the topsoil annually. When 1 ton of manure is applied, only 90 kg of humus is formed in the soil. And if 1 ton of straw is left on the field, 170 kg of humus is formed in the soil. Those. just to replenish annual losses and maintain a deficit-free humus balance, only in the arable layer it is necessary to apply at least 10 t / ha of manure. This amount is not acceptable. Plant residues are the best alternative to replenish the organic content in the soil.

All these tasks can be solved through the transition to zero technology.

No-till is an abbreviated name for zero-technology in crop production, in which seeds are sown in the soil that has not been subjected to any treatment.

When the soil remains intact and covered with plant debris, the abundance of all types of soil organisms (from microbes and fungi to arthropods) increases. With more organic matter and better infiltration, no-till conserves the soil.

Reducing soil operations using No-till technology leads to savings in time, labor, and fuel. It is the No-till technology that allows the farmer to work less, earn more and at the same time preserve his precious land.

That is why this technology has spread so widely around the world over the past 20 years. Find at least one more technology that is more soil-friendly! It is zero technology that is the most effective way to prevent soil degradation and restore its productivity.

If at the first stage of mastering this technology, farmers solve the problem of protecting the soil from erosion and preserving the existing level of soil fertility, then in the future, the task of increasing soil fertility becomes a new priority in their work.

Scientists around the world are paying attention to one of the main reasons for the decline in soil fertility:

“Land productivity is declining dramatically due to soil erosion, salt build-up and nutrient depletion.

Continuous tillage over a long period of time destroys bacteria and microorganisms that convert organic matter into nutrients. "

Professor Mary Scholes and Associate Professor Bob Scholes

from the University of the Witwatersrand (South Africa)

Therefore, in order to effectively work to improve soil fertility, you need to turn your attention to microorganisms that live in the soil.

Soil microorganisms - converters of organic substances into nutrients.

When, during the development of zero technology, we stop disturbing the soil cover and leave all plant residues, very favorable conditions are created on the soil surface for the development of soil biota, which contributes to soil restoration. But when we harvest the cultivated crop, soil bacteria lose their source of nutrition, as they feed on the readily available carbon that the living roots release during photosynthesis. So, the process of development of soil microorganisms slows down until the next year - until the next cycle of growing cultivated plants.

If we want to not only preserve the existing soil fertility, which in itself is the number one task for many farmers, but rather increase its level, we need to literally feed the soil biota during a period when commercial crops are not grown in the field. What is needed for this?

To do this, you need to always have living roots in the soil, and on the surface - a permanent vegetation cover or, in extreme cases, mulch. For this purpose, cover crops should be sown every year after the main crop is harvested. On dry land, plant residues must be crushed and left in the form of mulch on the surface of the field.

Cover crops at the Dragmi farm, sown after harvesting winter barley.

Cover crops have many properties that are very important for soil fertility. They are capable of:

- to increase the content of organic matter in the soil, which contributes to an increase in the content of organic carbon in the soil;
- to increase the number and activity of beneficial soil organisms;
- to accumulate plant residues on the soil surface;
- to loosen and improve the structure of the soil;
- improve air and water conditions;
- to increase the water-holding capacity of the soil layer;
- to produce nitrogen by biological fixation (legumes);
- restrain the development of weeds;
- protect the soil from soil erosion (water and wind) and overheating;
- circulate nutrients in the soil;
- trap snow and other precipitation;
- to simplify problems with pests and diseases.

They produce large amounts of plant biomass and roots when the main cash crop is harvested. This contributes to an increase in the number and activity of beneficial soil microorganisms. This is very important, since it is the increase in the number of bacteria in the soil that leads to an increase in its fertility.

The soil surface should never be bare!

Crop cover crops

Although cover crops (green manure) are just one of many elements of No-till technology, this element must be prioritized to increase soil fertility. Working on it, you can get the fastest results, since growing cover crops will entail changes in the entire No-till system: it will tighten such elements as "crop residues", "weed control", "soil moisture", "nutrients", " crop rotation ”, and will make this system more balanced and harmonious.

Including cover crops in the crop rotation, there are many ways to go. These can be both mowing crops1 and binary crops2. Cover crops can be grown both in monoculture and in mixtures (so called “cocktails”), which is an even better alternative. But with all these possible options for growing cover crops, the main principle must be observed - there are always live roots in the soil, and on the surface there is a permanent vegetation cover.

Topsoil section with cover crops

This is how a zero-seed drill works.

The disc coulter cuts crop residues and sows seeds next.

  1. Mowing crops - those crops that are sown after harvesting annual main crops to obtain "green mass". The harvest is increased by autumn and harvested. Various legumes and cereals, as well as their mixtures, can be used as cuttings.
  2. Binary crops - growing two crops at the same time in the same field. For example, sunflower and alfalfa are planted in the same field. Alfalfa completely covers the soil in the intervals between sunflowers and creates a green mass that has great benefits - the accumulation of organic matter in the soil, improving its structure, moisture retention, nitrogen accumulation in the soil for future harvest, and others.