How to increase soil fertility while reducing the cost of money and labor

Initially, these processes have a positive effect on plant growth and harvest. However, in the long term, traditional farming gradually kills the soil – the foundation of food security.

The problem of preserving soil fertility is acute all over the world. That is why it is so important to switch to soil conservation agriculture, notes Alexey Volkov, national coordinator of the Global Environment Facility Small Grants Program (GEF SGP). In an interview with Gazeta.uz, he spoke about the difference between traditional and soil conservation agriculture, as well as about GEF SGP projects aimed at using new methods of land cultivation.

Why is traditional tillage detrimental to the soil?

Destruction of soil microfauna. Soil fertility directly depends on the microorganisms that live in it. There are 4 to 10 tons of living organisms per hectare of arable land: bacteria, fungi, insects, protozoa, worms, and others. Many of them need an oxygen-free environment to survive. When agricultural machinery turns over a layer of soil during cultivation, oxygen gets into it. This literally kills the microorganisms themselves and destroys their habitat.

Photo: FAO Uzbekistan.

“Unfortunately, most farmers do not think about the importance of soil fauna, while it is the basis for preserving the soil and the harvest. It is these microorganisms that “make” money for these farmers,” notes Alexey Volkov.

The harvest of some cereals and other crops occurs in the summer. After harvesting, the soil is usually prepared for sowing the next crop. Its inner layer is on the surface after plowing. A large difference in temperature between the external environment and the inner soil layer has a negative effect on beneficial soil microorganisms, which die in the heat.

Water loss. The bare, plowed soil is exposed to the sun. This accelerates the evaporation of natural moisture. Farmers make up for its deficit by irrigation. That is, we take water from rivers to irrigate our lands, which we ourselves previously dried out by tilling the soil. This water could be used to irrigate other lands, feed tugai forests, and even replenish the Aral Sea and rivers.

Water and wind erosion of soil. Mechanical processing crushes the soil. This change in structure leads to it being easily blown away by the wind. This process is called wind erosion. It manifests itself in more frequent dust storms, which has become well known to residents of Uzbekistan in recent times. Crushed soil is also easily washed away by irrigation water and carried away by the flow into rivers.

Dust storm on the horizon. Wind blows soil away from the field. Photo: Alexey Volkov.

“It takes microorganisms up to 150 years to create one centimeter of fertile soil layer. With traditional farming, we lose a century and a half of microorganisms’ work in a year,” emphasizes Alexey Volkov.

Traces of water erosion on a field. Water has washed away the soil. Photo: Alexey Volkov.

Removing plant residues and loss of organic matter. After harvesting, it is common practice in Uzbekistan to remove all plant residues from the field. They are usually used to feed livestock, forgetting that the land also needs to be fed. After removing plant residues, farmers plow the land, leaving the “bare” soil under the scorching sun and wind, which, as noted above, leads to erosion and drying out of the soil.

Bare soil. Photo: Alexey Volkov.

Fields are often set on fire to remove all plant residues. Fire dries out the soil even more, smoke pollutes the air, and the soil does not receive the organic matter that each harvest sucks out.

“Unfortunately, farmers do not understand the biology of soil and plants. Many find it convenient to ‘clean’ the field of plant residues,” says Alexey Volkov.

However, plant remains are necessary for the soil. Firstly, they protect it from the sun, preventing excessive heating of the earth and evaporation of precious moisture. Secondly, microorganisms living in the soil process these remains into humus and nourish the earth with organic matter, says Alexey Volkov.

“Farmers remove all residues from the soil surface, but the roots remain. And this is also very good. Roots are food for soil microorganisms, this is organic matter. But roots alone are still not enough. A lot of organic residues are needed, because each harvest is a loss of organic matter, and it needs to be replenished,” notes Alexey Volkov.

Annual humus losses from the arable layer amount to about 760 kg/ha, according to the GEF SGP newsletter . To compensate for these losses, at least 50 c/ha of dry organic material from post-harvest residues is required. However, farmers prefer chemical fertilizers, since plant residues are used as livestock feed. Chemical fertilizers are ineffective because they do not serve to preserve soil fertility, but act as an energy supplement for crops.

Overwatering. Despite the growing water shortage, every farmer who has access to water tries to apply as much liquid to the field as possible. However, according to Volkov, almost no farmer thinks about preserving moisture in the soil. This leads to other farmers not having enough water.

Flushing the field from salts. Photo: Alexey Volkov.

In regions with high soil salinity, farmers wash out salts by flooding their fields with water. To do this, they use 3,000-6,000 cubic meters of water per season. However, the soil becomes even more saline because, firstly, the level of mineralization of water for irrigation of agricultural lands is initially high. Secondly, excessive irrigation raises the level of underground waters, which also contain a lot of salt.

After the moisture evaporates, all the salt lifted from the ground remains in the surface layer of the soil, making it unusable again. This motivates farmers to carry out leaching the following season.

“A vicious circle that no one can break, although there is a solution ,” says Alexey Volkov.

Lack of crop rotation. Most farmers do not pay much attention to the importance of crop rotation and grow one or two crops on the same land for years. This is also due to the planned economy in agriculture: farmers are given a plan for growing cotton and wheat. Due to the established land use policy, farmers are not the full owners of agricultural land and always risk losing their fields if the required plan for cotton and wheat is not met. This further reduces the motivation of farmers to use crop rotation.

Crop rotation allows the soil to recover. If the soil produces wheat, cotton, or any other crop year after year, it uses up the micronutrients needed to grow that crop and accumulates pathogens that feed on that crop. Scientifically based crop rotation allows the soil to use its full potential and gives the soil a chance to recover. Sustainable and soil-protective agriculture involves growing crops in rotation that work to increase each other’s yields.

“Crop rotation is also important because crops have different root systems,” explains Alexey Volkov. “Some roots go deep, others spread out to the sides – this is how the soil is loosened. That is, you don’t need machinery to loosen the soil, you need the right plants. After all, in nature there are no tractors with plows, and the soil is fertile and healthy. Man will never come up with something smarter than nature.”

Soil compaction. Each operation of soil cultivation by the traditional method is carried out with the help of agricultural machinery. Despite the loosening of the soil, under the weight of tractors and combines the earth, on the contrary, is compacted. For sowing crops, the soil is loosened only at the coarse macro level. However, under the pressure of heavy agricultural machinery, there is a general compaction of the soil between the particles that form the soil framework.

Sirozh Aslonov / UzA.

Compaction between soil particles negatively affects the life of microorganisms and the ability of the soil to retain and pass moisture, as well as air. These soil properties directly affect soil fertility and crop yield. In addition, soil compaction requires large expenditures of water resources, because dense soil cannot retain moisture and requires more water.

“All this suggests that traditional soil cultivation leads to the destruction of biological and physiological qualities of the soil, to salinization and loss of moisture, humus, and soil fertility. This is expressed in the loss of crop yields and money, which affects farmers and the country’s economy,” says Alexey Volkov. “The only way out can be soil-protective agriculture, in which equipment travels across the field five times less than with traditional land cultivation.”

What is conservation agriculture?

Conservation agriculture helps to preserve moisture, microorganisms and the growth of organic matter (humus) in the soil. It saves precious water, increases fertility, and therefore ensures food security, and also reduces farmers’ costs.

This is achieved through:

• permanent covering of the soil with plant residues;

• crop rotation, which helps to increase soil fertility;

• long-term zero tillage.

No-till, or zero-seeding, means that one mechanical operation is performed to sow crops instead of five.

Agricultural machinery is used only for sowing crops. For this purpose, a special seeder drives across the field, making a thin cut in the soil with a blade and placing seeds in it at the required depth. The soil is not disturbed by plowing and loosening, all its microfauna is preserved. This forms the natural structure of the soil, retains moisture in it, protects it from the sun and wind, and prevents wind and water erosion.

A zero seeder purchased by the GEF SGP as part of one of the conservation agriculture projects. Photo: Alexey Volkov.

It is important to keep plant residues in the field and sow a second or even third crop per year so that the soil is always covered with plants or mulch (chopped plant residues). This will protect it from drying out, overheating and blowing away. In addition, mulching the soil retains a huge amount of moisture in the soil and saves water for irrigation.

The moisture retained in the soil due to mulch is used by plants during the growing season, reducing both the need for irrigation and the water consumption for washing fields from salt and the accumulation of salts in the soil. Mulching allows reducing water consumption for washing by 2000 m³ per year and reduces mineralization by 1.6-4 times.

Another important advantage of mulching is soil nutrition. Plant residues add organic matter that our soils lack. According to Mirzaakhmat Usarov, chief designer of the Yangiyul Research Institute of Agricultural Mechanization, a ton of straw gives the soil 170-180 kg of humus, which is twice as much as a ton of manure.

According to Alexey Volkov, the big disadvantage of zero seeding is weeds. The fight against them becomes more difficult, but in the long term of several years it gives its results. If plant residues and herbicides are managed correctly, then after several years of continuous mulching, farmers manage to significantly suppress weeds.

Mulch cut by a no-till drill disc for sowing crops. Photo: Alexey Volkov.

The combined benefits of conservation agriculture improve the chemical, physical and biological condition of the soil, reduce water consumption and negative impact on the environment. But the most interesting thing is that zero tillage significantly reduces farmers’ costs for fuel, equipment, labor, and their time. Refusal of traditional methods of land cultivation saves about two weeks of pre-planting work, which allows to improve the yield of the second crop per year.

“It takes 10-15 days to cultivate the land for each crop,” says Alexey Volkov. “With zero sowing, refusing two cultivations adds almost 30 days to the crop’s ripening time: it receives more positive temperatures, time to ripen. It turns out that the crop can either be harvested earlier, or it will be stronger and fatter. Let’s say our wheat is winter wheat. It is sown in the fall, before winter, and harvested in June. If, due to zero sowing, wheat is harvested in the first half of June, and then another crop is sown and another two weeks are not spent on cultivation, the second crop gets more time and produces a larger harvest.”

According to Volkov, in Uzbekistan, corn is often sown after wheat. Due to the time lost in cultivating the land, the second crop sometimes does not have time to ripen. Zero sowing gives crops up to a month of additional time.

“Of course, two harvests are not guaranteed, it depends on the crop. But with zero chances of collecting more harvest than with traditional processing,” says Alexey Volkov.

Among other advantages, Alexey Volkov cites the independence of farmers from precipitation on dry lands.

Dryland lands in the Kitab district of the Kashkadarya region.

“On such lands, you can sow only when the soil receives a certain amount of precipitation. Farmers cannot begin to cultivate the land, they delay sowing until later dates – October, November, sometimes December. Very often they do not have time, because a lot of precipitation can fall at once, and nothing can be done with this land. Farmers of dry lands are very dependent on the weather and precipitation. At zero, they do not need to wait for anything. They can sow the crop at any time. As soon as the first precipitation falls, the seeds will begin to germinate. The ripening time of the crop is completely different. And the yield will be higher, because the plants will receive more moisture, more time to grow, and will gain more strength. On dry lands, the use of zero tillage is especially economically advantageous.”

As for irrigated lands, they are basically independent of precipitation, explains Alexey Volkov. They can be watered at any time, so they can be cultivated at any time – the main thing is to sow on time.

“But saving water for irrigation is very important in our conditions. The more you save on irrigation, the more water will be available for irrigation of other lands. It will be possible to irrigate more lands and get more harvest.”

What prevents us from switching to zero tillage?

The main barrier to the transition from traditional to conservation agriculture is the millennia-old traditions of cultivating the land that will have to be abandoned. For the transition to be successful, farmers, scientists, and politicians must believe that the land can be cultivated not by tractors and ploughs, but by plant roots, soil organisms, the freezing and thawing cycles of soil layers – everyone must believe that nature can cope on its own. It just needs help.

Photo: Khotam Mamadaliev / UzA.

“To believe in zero tillage, just look at the loose soil on the edge of fields that have never been ploughed. How wild plants grow here! If you sow cotton here, it will grow well – compare it to cotton in a ploughed field,” note specialists from the Agricultural Mechanization Research Institute.

Another barrier is farmers’ limited access to machinery. As a rule, it is primarily allocated for sowing strategic crops – wheat and cotton. A lot of time is spent on cultivating the land. Sometimes farmers are late with sowing because they do not have enough machinery for all operations and for all the land. Late sowing “steals” time for the crop to ripen, which means farmers will not receive the benefit of their work. With zero sowing, this problem is leveled out.

A planned economy in agriculture means that farmers growing strategic crops receive more administrative support. However, support is also needed at the “zero” level – this is a question of food security, emphasizes Alexey Volkov.

Weeds

In traditional tillage, farmers physically destroy weeds by using agricultural machinery to process the fields. This is impossible with no-till, so “farmers need to know each weed by name and the herbicides that are appropriate for each weed,” says Alexey Volkov.

“‘Herbicide’ sounds unecological. But here we need to understand that weeds can even increase soil fertility. They are the same organic matter. Proper weed management with the help of competent use of herbicides will destroy weeds, will not allow them to grow, but will add all the biomass to the plate of soil microfauna, which will transform these plants into humus,” notes Alexey Volkov.

Some farmers even choose to ignore weeds, he says. By completely covering the soil with mulch, they disappear completely or cease to be a problem within three years.

“There is no light under the mulch, the temperature is lower than on the surface, and weed seeds simply cannot germinate,” explained Alexey Volkov. “It turns out that in early spring before sowing, when the weeds should have already sprouted, they are not there because the young generation is stifled. As soon as the temperature, light and moisture allow you to sow the crop, you sow. And it takes over the weeds, simply because there is more of it – it’s competition.”

Diseases

Various plant diseases pose a great threat to the harvest with any method of cultivation. With traditional cultivation in the absence of crop rotation, harmful microorganisms and pathogens accumulate in the soil, which adapt to one crop. They pose a threat to future harvests if they are not controlled with chemicals.

With no-till, diseases can remain in plant debris and spread from incompletely decomposed debris to germinating plants.

However, this can be avoided by introducing crop rotation, a condition that is necessary at “zero” in any case. Crop rotation helps fight diseases because the root secretions of different plants form different communities of microorganisms and soil inhabitants. They do not allow harmful pathogens to accumulate in the soil in critical quantities.

Introduction of zero sowing in Uzbekistan

The GEF SGP co-financed a number of projects to introduce conservation agriculture in Karakalpakstan, Bukhara, Jizzakh, Tashkent, Namangan and Fergana regions.

One of these projects was implemented on the dry lands of the Gallyaral Scientific Experimental Station of the Research Institute of Grain and Leguminous Crops. The lands here are extremely dry, suitable for growing only non-irrigated crops.

For the project, in 2019, the GEF SGP purchased two Brazilian-made no-till seeders for the institute, each costing $25,000. An economic analysis of the project showed that if the cost of purchasing equipment is converted to 1 hectare of processed area, the costs amount to only 86 thousand soums per hectare per year.

Soybeans planted using the zero-till method on dry lands of the Gallaral Scientific Experimental Station of the Research Institute of Grain and Leguminous Crops.

Compared with traditional tillage, no-till technology reduced labor, fuel and technical costs by 30–40%, increased wheat yield by 25%, and net profit by 50%.

Alexey Volkov warns that in the first years of using no-till, crop yields may be somewhat lower, since the soil needs time to recover.

“The soil must become healthy, begin to live, microorganisms must appear, it must become ‘loose’,” he explains. “With traditional tillage, it is made loose by a harrow and a chisel (special tractor units – ed. ). With zero seeding, the soil becomes like this thanks to mulching and the work of microorganisms, worms, rotting, restoration of biological connections in the soil. The more alive the soil is, the more it resembles a sponge. On average, this takes five years.”

Along with some reduction in yield, profitability will increase, Alexey Volkov continues. At “zero”, farmers do not need to rent equipment for several operations of field processing, do not need to pay for labor, and fuel costs are reduced.

In addition, the costs of purchasing “zero-till equipment” can be reduced by establishing equipment production in Uzbekistan. The Research Institute of Agricultural Mechanization in the Yangiyul district of the Tashkent region has been developing such equipment in the country for 90 years. The institute’s employees invent new technologies and equipment for the mechanization of various agricultural processes, and also adapt imported equipment to local conditions.

With the collapse of the Soviet Union, the research institute lost several workshops and a plant and was left with only workshops where it manufactures various units using a minimal set of tools. The institute is supported by the Ministry of Agriculture, but the funding only covers the salaries of exclusively scientific employees, who make up half of the staff of the research institute.

The institute’s main expenses are covered by the income of five regional melioration centers – organizations that lease agricultural equipment to farmers. The research institute has no money for scientific and research activities. Therefore, the organization turned to the GEF SGP with a request to purchase equipment that will allow it to invent equipment, including for zero tillage.

Delivery of equipment purchased by the GEF SGP for the invention of agricultural machinery mechanization for soil conservation agriculture at the Research Institute. Photo: GEF SGP Telegram channel.

This will also increase the extra-budgetary income of the research institute, which can be directed to science, noted the scientific secretary of the institute, Abdurasuly Ibragimov. According to him, the Ministry of Agriculture does not particularly finance new developments and research. Their implementation is possible only with grant funds, which are raffled off by the Ministry of Innovations and international organizations, including the GEF SGP.

“The country’s leadership is thinking about water conservation, so it is very important to switch to soil-protective agriculture, to think about what the soil wants, what the crops being grown want,” explains Alexey Volkov.

Zero seeder at the Research Institute of Mechanization.

Switching to zero tillage requires meticulous planning. To avoid shock, the GEF SGP recommends approaching the changes step by step ( instructions ). In addition, a radical change in land cultivation methods requires study: you need to learn how to manage crop residues, crop rotation, and properly combat weeds, says Alexey Volkov.

“Despite all the difficulties, the transition is necessary, it needs to be started, because ultimately the reorientation will result in the country preserving cubic kilometers of water, increasing soil fertility and bringing in a lot of money. It is not easy to calculate, but it is quite realistic,” notes Alexey Volkov.

https://www.gazeta.uz/ru/2023/10/19/soil-fertility/

Machine Translated by Google