How to use crop residues and at the same time increase the content of phosphorus available to plants?

Crop residues are all the remaining organic matter in a given crop site after harvesting, also called secondary yield. They consist of roots and above-ground parts of plants, such as seed pods, stems and leaves. As a natural organic material, they are a very rich source of nutrients. Their proper use enables an increase in the humus content and improves the soil's microbiological activity.

Most crop residues are mature or dried blades and stems, i.e. straw. The amount that remains after cultivating depends on many factors, mainly the species and variety of the crop, as well as climatic and soil conditions, fertilizers or growth regulators used, and the date and accuracy of harvesting. One of the methods of determining straw yields is to calculate its amount based on the grain yields obtained. For cereals, the grain to straw ratio ranges from 1:1.0 - 1.5, while for corn it is 1:1.5, and for rapeseed even 1:2.0. At the same time, in the case of grain, winter varieties show higher straw yields by up to 20-37% than spring varieties.

The use of straw depends on the needs of a given farm. It is most often used as animal feed and bedding, but there is also an increase in its use for fertilizer purposes. Its fertilizing value depends on the species of the cultivated plant and varies depending on the grain yield obtained. It is a valuable source of macro- and microelements, especially potassium (K). Straw obtained from corn, buckwheat, legumes and rapeseed is the richest in nutrients compared to grain straw. Among grain straws, barley and oat straw have the highest fertilizing value.

 Based on Dorota P. "The impact of long-term straw fertilization on plant yields and soil fertility" [IUNG-PIB Report].

The beneficial effects of straw on the soil properties are evident for 3-4 years after its application. However, it is not high in the case of phosphorus, as in the first year about 15-30% of this element is released into the soil. In the case of potassium it is 50-70%, and for nitrogen up to 70%. When rotating from plowed-in residues, the use of phosphorus increases to 50-60%, and potassium up to 90%. In order for these components to be used by plants, organic matter must be transformed into forms available to them as quickly as possible. The rate of decomposition of crop residues is determined by the nitrogen content, the carbon to nitrogen ratio (C:N) and the lignin content, which determine the susceptibility of the carbon compounds contained in the residues to microbial decomposition. The higher the nitrogen content in the first phase of decomposition, the higher the rate of mineralization of crop residues, while during advanced decomposition the lignin content is decisive. In addition to the chemical composition, decomposition also depends on factors influencing the activity of microorganisms, such as temperature, soil reaction, air and water conditions and the content of minerals, as well as the presence of compounds in the soil that are harmful to plants or the species of the plant being cultivated.

The natural decomposition of crop residues is a long-term process, which causes the release of elements into the soil slowly and, consequently, their availability to plants is staggered over time, therefore it is recommended to use appropriate formulations to accelerate the mineralization of crop residues, such as DECOMPOSE AND RELEASE.

DECOMPOSE AND RELEASE works in two ways: it activates biological processes in the soil, thereby intensifying the decomposition of organic matter, and transforms complex and insoluble forms of phosphorus, such as calcium phosphate, into easily digestible forms, increasing the availability of this element for plants. The product is based on specially selected bacteria of the Bacillus sp. genus and additional ingredients that have a beneficial effect on the activity of microorganisms that accelerate the mineralization of organic matter.

Phosphorus (P), as one of the three essential macroelements, which is also very poorly absorbable, is crucial for plant growth and stimulating root development, enhancing nutrients and water uptake, as well as stabilizing the plant in the substrate. It has a particularly positive effect on the proper course of photosynthesis and other energy processes taking place in plants, as well as the resistance of plants to unfavorable conditions in fields. As a result of phosphorus deficiency, plants significantly slow down their growth rate and become darker. Long-term deficiency of this component in plants causes them to undergrow and have a poorly developed root system.

Phosphorus is needed by plants from the seedling stage to full maturity, but plants absorb it only in the form of hydrogen phosphate ions H₂PO₄- and HPO₄², and the soil itself is not rich in this macronutrient. The concentration of phosphorus in the soil is in the range of 500-800 mg/kg of dry soil, and its average content is 0.05% (w/w). Approximately 60% of soils in Poland are characterized by low or very low content of phosphorus available to plants, and this form constitutes on average only 0.1% of all phosphorus in the soil. Research carried out as part of the "Monitoring the chemistry of Polish arable soils" programme showed that the content of available phosphorus has decreased over several years and its average content expressed as phosphorus pentoxide is 14.65 mg P2O5·100g-1. The factors that influence the absorption of this element are the soil reaction, the content of iron and aluminum compounds, the presence of available calcium and the content of organic substance. The largest amount of it is found in the subsurface layers of soil, and it decreases with the depth of the soil profile. Attention is increasingly paid to the activation of natural mechanisms that increase the bioavailability of phosphorus present in the soil (native and retrograde) due to the fact that a much larger amount of this macronutrient occurs in forms unavailable to plants, and the important role of bacteria in these processes.

The bacteria contained in DECOMPOSE AND RELEASE from the Bacillus sp. genus are known as phosphorus bacteria that transform phosphorus compounds from forms that are inaccessible, and therefore blocked for plants, to forms that are available to them. They secrete enzymes into the soil i.e. phosphatases and phytases, which hydrolyze and mineralize organic compounds. The enzymatic activity of bacteria leads to the transformation of organic phosphorus into inorganic phosphorus, which is available to plants in ionic form. Phosphorus bacteria additionally introduce many substances into the soil that promote plant growth, such as siderophores, auxins, cytokines and vitamins.

The effectiveness of the DECOMPOSE AND RELEASE product in accelerating the decomposition of crop residues and increasing the amount of phosphorus available to plants, as a result of the action of the bacteria contained in it, is confirmed by tests performed in our test laboratory.

Field conditions were reproduced in a phytotron chamber and an analysis of the phosphorus content in the soil was performed before and after application of the formulation at a dose of 2 kg/ha/200l after three weeks.

Advantages of using DECOMPOSE AND RELEASE

• accelerated mineralization of crop residues,
• improvement of soil fertility,
• increasing the content of humus and organic substances in the soil,
• increasing the amount of macroelements in the soil,
• increasing the availability of available forms of phosphorus for plants,
• proper plant growth and root development.

Composition

Bacteria of the Bacillus sp. genus in a concentration of ≥ 2×109 CFU/g.

The product additionally contains nitrogen (N) - 14%, boron (B) - 3%, iron (Fe) - 1.5% and molybdenum (Mo) - 0.6%.