The scientific background for using straw for fertilizer is as follows.
- Straw - a source of nutrients. The chemical composition of straw varies widely depending on soil and weather conditions. On average, it contains 0.5% nitrogen, 0.25 phosphorus (P2O5), 0.8 potassium (K20), and 35-40% carbon in the form of various organic compounds. In the straw there are some amounts of sulfur, calcium, magnesium, various trace elements (boron, copper, manganese, molybdenum, zinc, cobalt, etc.).
At average grain yields (20–30 t / ha), 10–15 kg of nitrogen, 5–8 phosphorus (P2O5), 18–24 kg of potassium (K20), and the corresponding amount of trace elements will be returned to the soil with straw.
- Straw is an active energetic material for the formation of soil humus and an increase in soil microbiological activity. By chemical composition, cereal straw is characterized by a rather high amount of nitrogen-free substances (cellulose, hemicellulose, lignin) and a low content of nitrogen and mineral elements. The wide C: N ratio in straw (70-80) has a great influence on its decomposition in the soil. It consists in the following. The straw supplies the soil microflora with a readily available source of carbon. Cellulose decomposing microorganisms have a relatively high need for nitrogen. Given the small amount of it in the straw, microorganisms consume mineral nitrogen from the soil, i.e. The process of immobilization of nitrogen. If there is a limited amount of soil nitrogen, then the decomposition of straw is inhibited. It was established that for the normal course of the decomposition of straw, the C: N ratio should be 20-30: 1. A narrower ratio of these elements leads to the mineralization of nitrogenous compounds, and a wider one enhances the processes of nitrogen immobilization.
Straw fertilizer efficiency increases markedly with additional nitrogen addition. A comparative evaluation of straw fertilizer with nitrogen compensation and manure shows their close effectiveness. It is important here that the C: N ratio equal to 20: 1 is achieved with the straw and nitrogen introduced.
When composting straw under aerobic conditions, the yield of humus was 7.9%, and when mineral nitrogen was added to straw, it was 8.5% of the total mass of straw. Humus is formed most intensively during the first 4 months of composting, during the decomposition of cellulose and hemicellulose. Moreover, humus accumulates in the maximum amount during the period of the highest number of microorganisms, which indicates their involvement in the formation of humus.
In combination with the appropriate mineral fertilizer, liquid manure or with leguminous crops used as green manure, the effect on the humus content in the soil is often not inferior to the equivalent amount of manure.
- The use of straw for fertilizer improves the physicochemical properties of the soil, reduces nitrogen losses, increases the availability of phosphates and the biological activity of the soil, resulting in improved nutritional conditions for plants. The positive effect of straw on soil fertility and crop harvest is possible if the necessary conditions are available for its decomposition. Thus, the speed of microbial decomposition of straw depends on the presence in the soil of food sources for microorganisms, their number, species composition and activity, type of soil, its cultivation, temperature, humidity, aeration, etc. For example, the decomposition of straw increases with the introduction of various nitrogen sources, additional the introduction of phosphorus on soils poor in phosphorus, the introduction of trace elements such as manganese, molybdenum, boron, copper, etc.
It was also noted that the intensity of the decomposition of fiber increases from sod-podzolic soils to gray forest and chernozem. The optimal decomposition temperature of fiber is 28-30 ° C and the soil moisture is 60-70% of its full moisture capacity. The intensity of decomposition of straw in the upper soil layer is noticeably higher, which is explained by good soil aeration, as well as by the large number and diversity of the species composition of microorganisms.
The introduction of straw into the soil enhances the nitrogen-fixing ability, the enzymatic activity of the soil.
- Often in the first year of making straw the yield of cereal crops is reduced. This is explained by the presence in the straw and the formation of toxic compounds in the process of its decomposition, as well as the deterioration of the conditions of nitrogen nutrition of plants when the soil nitrogen is fixed by microorganisms due to the wide ratio in straw C: N.
Straw fertilizer is of particular importance for leguminous crops that fix atmospheric molecular nitrogen. A higher effect of straw is obtained by treating the seeds of legumes with nitragin; therefore, it is advisable to place first of all legumes or row crops in areas fertilized with straw.
Stubbed soil in advance stimulates the nitrogen-fixing capacity of legumes and significantly increases their yield. Nourishment of tilled crops is ensured by mobilizing the nitrogen of the soil during its inter-row treatments.
- Nitrogen fertilizer reduces the depressant effect of straw on cereals. The nitrogen of mineral fertilizers immobilized in the presence of straw is characterized by greater mobility, less resistance to acid hydrolysis, and is more mineralized than nitrogen immobilized without straw, especially humus nitrogen. In the aftereffect of straw, the processes of nitrogen mobilization in the soil are enhanced, the use of both the immobilized nitrogen of the fertilizers and the nitrogen of the soil increases by the plants, which determines its positive effect on the yield of subsequent crops.
There are several ways to use straw for fertilizer.
- The straw that is crushed and scattered across the field is plowed in the fall when the zyabi is raised or in the spring in areas of sufficient moisture. It is advisable to combine this technique with green fertilizer. This allows in most cases to exclude the introduction of mineral nitrogen fertilizer, and also creates favorable conditions for the formation of humus in the soil after plowing.
- On soils of heavy particle size distribution and in humid climatic conditions, the straw scattered across the field is not plowed, but is buried by surface plowing, a disc harrow or a milling cutter.
Fig. 6.2. Methods of making and methods of embedding straw
Mineral nitrogen fertilizers can be replaced with loose liquid manure at the rate of not less than 6-8 tons per 1 ton of straw. With this combination, this fertilizer will act no worse than the usual litter manure.
The use of straw for fertilizer with the addition of a small amount of mineral nitrogen, or in combination with manure-free dung or green fertilizer, has been tested in many republics and in soil and climatic conditions and has given a good positive effect. For example, in Belarus, on typical for the republic sod-podzolic, highly podzolized soils, on light loams and on light sandy loams, separate application of 3 t / ha of chopped straw into the soil and 27 t / ha of liquid manure had almost the same effect on crop yield of crop link ( potatoes, barley, perennial grasses), as well as 30 t / ha of litter manure.
All this demonstrates the need for widespread use of excess straw for fertilizer as an important source of soil humus as a factor of its fertility. Schematically, ways to increase the efficiency of straw used as fertilizer are shown in Fig. 6.3.
WAYS TO IMPROVE THE EFFICIENCY OF STRAW USED AS ORGANIC FERTILIZER
Straw fertilizer is not a simple agricultural method. In order for it to become a truly valuable organic fertilizer, rather than a filler that interferes with tillage, the straw must be decomposed as soon as possible. Unfortunately, in most cases it is carried out fertilizer with gross technological violations. In particular, the straw is crushed and left for a long time on the surface of the soil. During this time, moisture reserves in the soil are quickly lost, the straw dries out, and its decomposition begins only after heavy rains.
The effectiveness of straw fertilizer depends on how it was crushed by a combine, scattered across the field and embedded in the soil. Therefore, it is necessary to remove the crop only with combines with choppers, observing the following requirements:
- cutting height when cleaning - no higher than 20 cm,
- The length of 75% of straw particles should not exceed 10 cm, and particles above 15 cm - no more than 5%,
- spread the straw along the field evenly, without creating rolls,
- Close up the straw with a disc harrow (BDT-7) to a depth of 12 cm immediately after harvesting the crop, preventing the soil from drying out. Sufficient moisture ensures the efficient operation of microorganisms and the rapid decomposition of straw,
- ammonium nitrate to make before embedding straw at the rate of N10/ ton of straw (approximately: 1 centner of nitrate per 1 hectare),
- be sure to spend the autumn plowing.
If chopping straw is not possible due to the lack of combines with choppers, then the problem can be solved by adjusting the height of the cut during harvesting. With direct combining, the height of the stubble can be 30 or even 40 cm, i.e. almost half of the straw still remains in the field, moreover, evenly distributed. After harvesting, such stubble is treated with heavy disc harrows.
Negative results are obtained when burning straw and stubble. This is an unacceptable manifestation of mismanagement, since in this case many useful microorganisms are destroyed and the potential fertility of the soil decreases sharply. Organic carbon and nitrogen are irretrievably lost. In addition, it causes great harm to the environment. Burning straw is perhaps the only agricultural factor in causing damage that equates to industrial emissions to the atmosphere.
A big mistake is the neglect of such an agricultural technique as the introduction of nitrogen into the soil. The fact is that the decomposition of straw requires microorganisms that have a protein nature. When they multiply to build cells of these microorganisms from the soil is removed nitrogen, which is replaced by protein. The ratio of carbon and nitrogen, which is different in different organic residues, is of great importance. Salinity will be complete if the ratio is 20: 1. In straw straw it is 50-100: 1. Under these conditions, the salinity (decomposition) of straw can last about two years. To reduce the C: N ratio, to improve the conditions of mineralization and to promote the active formation of the biomass of microorganisms, it is necessary to apply nitrogen fertilizers.
So, plowing straw without applying nitrogen fertilizers leads to a sharp decrease in the content of mineral nitrogen in the soil and a decrease in the yield of the following crops. And the introduction of straw in the amount of 35-40 t / ha with nitrogen compensation (at the rate of N10/ ton of straw) in terms of its effect on increasing soil fertility and crop yields is equivalent to adding 18–20 t / ha of manure.
A sufficient amount of phosphorus is also necessary for the vital activity of microorganisms: it is applied at the rate of P8 per each ton of straw, this is especially important on soils with insufficient content of available phosphorus. Here it is necessary to make phosphate and potash fertilizers. At high temperatures, phosphorus and potassium will more quickly form part of the soil complex and more efficiently be used by the next crop rotation (scheme).
Due to the mineralization of plant residues, a significant amount of nutrients are released from them, which are returned to the soil. For example, for every ton of grain with wheat straw plowed into the soil, N returns7P3K16Mg2, and for each ton of rapeseed with a plowed mass remains N14P6K40Mg3. Then the batteries make only the main part of the product - the grain. Approximate content of macro - and micronutrients in plant residues of the most common crops are presented in table 2.
The ratio of grain and straw, depending on the characteristics of the variety and the technology of cultivation, in winter wheat can be 1: 1.0-1.5. With a yield of 40 c / ha of grain per 1 hectare, 40–60 c of straw remains. Provided that straw contains 0.5% nitrogen, 0.2% phosphorus, 1% potassium, 0.3% calcium, 0.15% magnesium and sulfur, then approximately this number of macronutrients N will return to the soil with this amount of straw20-30P8-12K40-60Ca12-18Mg6-9S6-9
The calculation was made only on straw, and some of the organic matter remains in the form of stubble and the root system of plants.
The best results are obtained when combining the two methods of alternative organic fertilizer. After chopping and embedding the straw into the soil, it is necessary to sow green manure crops. Most often used cabbage species. Then the soil is filled with organic matter from two sources: straw and green mass. In addition, siderata, their root system and green mass contribute to the mineralization of straw, accelerating it. Late in the fall, the whole mass is plowed.
Provided an early harvest and sufficient moisture reserves in the soil, oilseed radish or white mustard in case of sowing from July 20 to August 10 form a high yield of green mass up to September 20-30. Therefore, this system of fertilizer with straw and green mass can be applied under winter crops.
Description and composition
Straw is dried up stalks of plants without leaves and flowers. It is divided into subspecies depending on what the straw is obtained from. We will not consider all kinds, but we will focus on wheat, barley, oat and pea.
Wheat belongs to the family of cereals and is one of the most important plants that are used for baking bread in many countries around the world. The chemical composition of wheat straw includes elements such as magnesium, iron, zinc, iodine, sodium, manganese, cobalt, as well as vitamin D and carotene. Wheat also contains vitamins B1-B4, B6 and B9.
Dry stalks of barley are rich in calcium, fiber, phosphorus, potassium, magnesium, iodine, iron and sodium. In addition, they have protein, lysine and biologically extract substances.
Oats are grown in many countries around the world for both feed and human nutrition. Dry oat stalks contain many nutrients that are good for harvest, such as protein, iron, cobalt, potassium, carotene, and more.
All these substances help the plants get the necessary amount of minerals that are so necessary for the emergence of a good harvest.
Pea - annual climbing plant. Dry grass from peas is rich in lysine, fiber and protein, it also has many trace elements, such as phosphorus, calcium, magnesium and others.
In addition, peas are rich in ascorbic acid and vitamins of group B, E, H, PP. Peas are irreplaceable due to the large amount of antioxidants contained in it.
Let's see exactly how straw affects the soil and yield. Consider each item separately.
In the soil during decomposition, dried grass turns into simple carbohydrates and protein compounds. Further decomposed into lysine and cellulose. Straw decomposes in the soil the faster, the more nitrogen in the earth.
Therefore, it is better to use this dried grass to enrich the land with nitrogen fertilizers. The proportion is as follows: 10-12 kg per 1 ton of straw. To this mixture decomposed even faster, it is better to add manure to it. This increases the activity of microorganisms, which means that the process of decomposition will begin to flow even more intensively.
The decomposition of dry grass has a bad effect on the root system of plants, as this results in formic, benzene, lactic, acetic and other acids entering the ground, which hinder the development of the roots in plants.
However, by adding nitrogen to it, the negative effect on plants is eliminated. Due to the large amount of minerals, dry grass decomposes faster, as they are necessary for both microorganisms and higher plants.
The phosphorus content in dry grass is low, so it does not affect the soil as a whole. Let's touch where the dry stems of legumes and cereals are used in their pure form.
Use of pure straw
Cattle are fed with dry herbs. Due to the fact that this product is nourishing, it is given as a top dressing. For better absorption, dry herbs are ground, treated with chemicals (lime, ammonia, etc.) or steamed.
Granulation of straw along with artificially dried grass is also used.
Dry stalks of plants are used for bedding.
They are also good for making mats and slabs. In many museums of our country, straw is used to cover the roofs (Pirogovo open-air museum in Kiev).
Another use of dry stems of cereals and legumes is biofuel. They are also pressed into fuel pellets.
Sometimes straw is used to make paper (for example, banana). From it make baskets and nets.
In construction, straw is used to create straw blocks.
Кроме того, многим модницам нравится носить соломенные шляпки. Также из соломы делают сувениры. Использование соломы многогранно, но мы остановимся на ее применении в сельскохозяйственной промышленности, то есть создании из нее удобрений.
Приготовление удобрений из соломы
Широко применяется использование соломы в качестве мульчи и удобрения. Мульчирование означает дословно «укрытие почвы». This is done so that the earth does not overheat, and moisture is preserved on it.
Under the influence of the sun and rain, the earth loses a large amount of nutrients, and mulching prevents it. There is also a method: the use of dry grass as a fertilizer.
Before plowing dried stalks of legumes and cereals into the ground, they must be thoroughly crushed. The desired length of crushed dried plants should not exceed 10 cm (75%) and 15 cm (no more than 5%).
It must be remembered that the height of the cut should not exceed 20 cm. Lay dry stems 12 cm deep. After some time, you need to deepen the dried grass into the ground, but you can not do it right away, because it rotters slowly enough. That is why it is necessary for some time to hold the dried grass shallowly buried in the soil.
Good harvest results can be obtained by combining dry plants and sowing green manure. After plowing dry grass, siderats are sown. This gives the soil an additional source of organic matter.
In addition, this fertilizer mineralizes dry stalks of cereals and legumes, which will also affect the quality of the crop.
Advantages and disadvantages
And yet, let's see: the straw in the garden brings benefit or harm?
- Availability is in itself dried grass is of no interest in the agro-industry, therefore it is not used, but as a fertilizer it is simply indispensable.
- This fertilizer is more pleasant to use than dung.
- Spending less time and effort compared to other fertilizers (for example, manure).
- Easy to store.
- A large amount of organic matter.
- Increased earth friability.
- Improve soil moisture permeability.
- Arable land retains water better, and with it beneficial substances.
- Dry grass contains vitamins, physiologically active substances and amino acids.
- The carbon saturation of this fertilizer helps to further “breathe” the earth.
- Decaying, dry stems contribute extra carbon, due to which green plants grow.
- Protection of the earth from the sun.
- When using several types of straw increases the number of trace elements, which contributes to the full restoration of arable land.
Negative aspects of using this fertilizer:
- Insects can fall into fertilizer, which adversely affect the development and yield of the crop.
- Decomposing, dry stalks of cereals and legumes turn into acids harmful for the development of the crop.
- Dry grass contains many organic compounds, which require large amounts of water to decompose.
- Dried stalks of cereals decompose slowly and because of this beneficial substances will get to the plants for 3-5 years.
Straw and fertilizer - where is the connection?
Agronomists working with grain crops know that straw as a fertilizer is an excellent residual material for feeding the soil. In the autumn, it is plowed when perekop homestead plots, used as one of the components for the preparation of mulch and compost.
Inexperienced farmers practice straw burning in the fields. This action causes irreparable harm to the fertile surface. The temperature of the soil reaches extremely high levels, destroying worms, wood lice, loosening ground cover.
The smoke after combustion is equal in terms of environmental impact to emissions of harmful substances in industrial plants.
It is more efficient to use straw as an organic fertilizer: in comparison with manure, it is 4 times more economical.
The action is cumulative in nature: it will take about 8 months to get the result. The straw will possess phosphorus, magnesium, potassium, calcium, nitrogen. The latter component accelerates the process of rotting and the formation of humus, which increases the yield. Its ratio to carbon should be 20: 1.
Entering straw into the soil performs the following functions:
- increases fertility and soil structure,
- provides food to earth insects,
- activates nitrogen fixers,
- reduces soil erosion,
- improves soil absorption of water and air.
Straw protects the land from pests, from glaciation during the winter period, prevents its overheating, and also adds to the soil looseness and lightness due to the presence of carbon dioxide.
Dry organic helps to get rid of weeds, can be used on garden beds in the summer.
Description and properties
Straw - dried stalk of different cultures. It has the appearance of a tubule with an empty middle, is distinguished by a golden color and the absence of residues of rot, mold and fungus. Common crops for straw production are legumes and cereals.
Wheat contains iodine, manganese, magnesium and iron, sodium and cobalt, carotene, vitamins D, groups B. Element data are useful for the root system, stem, grain.
Barley is rich in fiber, calcium, lysine, protein, mass of extracts, vitamins A, PP.
It contains a lot of cobalt, iron, carotene, protein. Useful substances are absorbed into the plants when fertilized with oat organic matter.
Dry vine contains a large amount of lysine, protein, trace elements and vitamins, antioxidants. Fast rotting compared to other species.
Agronomists practice growing vegetables in straw, using it as a soil. The method is characterized by the lack of need for weeding, watering, hilling, fertilizing, pest control (Colorado beetles, etc.), making the cultivation of vegetable crops less cost-effective. Straw retains moisture, fertilizes plantings, prevents the emergence of weeds.
This method is most popular when growing potatoes. Planting begins with peat falling asleep in a trench 0.25 m deep, chaotic spreader of tubers and subsequent covering of the cultivated area with a straw layer of 35 cm. With a lack of rain, watering is necessary 1-2 times. With this approach, a rich harvest in the autumn will delight gardeners: the tubers will be even, unpolished, tasty.
The formation of the beds and the scaring off of it of rodents is carried out according to the following algorithm:
- Spread cardboard, paper, newspapers.
- Pour out wood ash (the other is not suitable) at the rate of 1 bucket per 5 m2.
- Place straw bales tightly, without gaps.
- 3 days to water, well soaking the structure with water.
- In the next 4 days to produce watering herbal infusion.
- Next, three days to moisten the soil with compost tea.
- After the specified period, the bed is loosely covered with a film for air circulation, leaving “windows”. After 10 days to plant the plants.
Alternative method of using dry grass as a bed:
- dig a trench half a meter deep
- lay out a layer of straw
- sprinkle with earth.
The considered method is suitable for growing strawberries, cucumbers, tomatoes, peppers.
- protection from freezing of land in winter, drought - in summer,
- prevent the emergence of large weeds,
- bait beneficial insects.
The soil becomes light, airy, optimally wet.
The disadvantage of using mulch is to reduce the nitrogen content in the soil, which leads to nitrogen starvation. Exit the situation using fertilizer based on this element.
Spring is the best time to mulch. It is better to plant seedlings that tolerate cold soil well: potatoes, cabbage, strawberries.
Feeding is carried out by sprinkling straw in the shape of a ball with a diameter of 15 cm. After a certain period of time, the layer will decrease to 4 cm.
The second option is to mix with rotten leaves, compost, different organic matter. On thick clay soil you need to lay out the mulch in a thin layer of 1-2 cm. For two weeks, add the next ball daily.
Loosen the soil necessarily.
To prepare this type of organic matter, you first need to determine its potential location. Then the material should be laid in layers in the following sequence:
chopped straw - 150 kg,
weeds or grass - 20 kg,
mineral solution: water - 40 l, superphosphate and potassium chloride - 6 kg each, saltpeter - 4 kg.
The compost pile overheats for a year, then it is mixed and put into the ground.
Straw is introduced in a dry form according to the rules:
- Maximum grinding: the cut should be 20 cm, the length of the straw - no more than 10 cm, the particle size - up to 5% of the volume.
- The introduction of mineral nitrogen.
- Hay scatter with a thin layer of smooth view without rollers.
- Plowing soil harvester designed for this purpose. Strawing is carried out immediately, the drying of black soil is not allowed.
The optimal period for entering straw as a fertilizer for a vegetable garden is autumn or spring. The post-harvest application makes it possible to store up to two weeks in the beds without perekop. Nitrogen is added before digging. After a few weeks, plowing is repeated.