How to judge the quality of soil? How to improve soil fertility?

We often call soil "Mother Earth" because it is the mother of crop production. To improve soil productivity, we must first understand the soil, know what fertile soil is, and then know what shortcomings the soil we cultivate has, and how to improve soil fertility and make it fertile. From understanding soil to understanding missing factors, from conservation to improving soil fertility, it is the basis to ensure crop yield and quality. Today we will talk about how to judge the quality of soil. And how to improve soil fertility!

Due to the differences in climate, farming system and soil parent materials, as well as fertilization and management methods, the soil characteristics of each region will be more or less different. Some have good fertility, while others have poor fertility. To improve soil fertility or fertility, we must first know what is wrong with this field or what is the reason for limiting yield. Next, we will list eight common land problems, which are explained as follows from the perspective of how to judge and how to solve them:

1. Improper soil pH and soil acidification

1, to judge the soil pH value: pH electrode method and litmus paper color method are commonly used. When determining pH value, soil should be mixed with water before determination, and it cannot be determined in dry soil, because the determination of soil pH value is actually the determination of hydrogen ion concentration in aqueous solution.

2. How to neutralize soil pH value:

Application of neutralizer: lime alkaline substances (such as agricultural lime, etc. ) should be suitable for acidic soil and acidic substances (such as sulfur powder and dilute sulfuric acid, etc.). ) should be applied to alkaline soil, and the neutralized soil should be improved by applying organic fertilizer. At the same time, the application of organic matter in acidic or alkaline soil is helpful to the availability of nutrient elements.

Emergency foliar fertilizer can temporarily improve the properties of soil that is over-acidic or over-alkaline, which is a temporary solution but not a permanent cure. Thoroughly improving the soil is the permanent cure.

Two. Lack of soil organic matter

1. Method for judging the lack of organic matter: besides testing and analyzing the content of soil organic matter by testing institutions, it can also be observed with naked eyes. For example, the soil becomes hard after drying, or the color is red and yellow, and there is no granular structure, which may be the characteristics of lack of organic matter. The more organic matter in the soil, the darker the color.

2. How to solve the lack of organic matter: it is necessary to apply organic matter or organic fertilizer to increase the source of soil organic matter, such as adding compost. Rotation should be adopted in planting, especially leguminous rotation is most beneficial to improve soil organic matter. In management, it is necessary to increase mulching and reduce soil erosion and topsoil loss, which is also one of the methods to maintain soil organic matter. When the paddy field is replanted, it is beneficial to the preservation of soil organic matter to reduce plowing and cultivate dry farming without soil preparation. In recent years, the application of humic acid has also contributed to the stability and increase of soil organic matter.

3. Poor physical properties of soil

1. Methods to judge the poor physical properties of soil: settlement mechanics analysis, floating scale method and hand-touch classification are commonly used to judge whether the soil texture (such as sand, ridges and clay) is too sticky or too sandy; Observe whether the soil pores are too dense. When touching by feeling, take a small amount of soil sample, wet it with water and rub it, which is sandy soil with gravel feeling; If you feel greasy, it means it contains high quality; Very sticky, but can be kneaded into strips, containing more sticky particles. The porosity of soil and the structure of clods or aggregates make it easy to observe the ventilation or drainage of soil with naked eyes.

2. Solve the problem of poor physical properties of soil:

Poor drainage: The economical method for poor regional drainage is to choose water-resistant crops or varieties, or plant them on high ridges. The drainage system can adopt simple drainage or pipeline drainage, and the construction of drainage system should pay special attention to the economic benefits such as drainage efficiency and service life.

Poor soil structure: If the soil porosity or aggregate structure is poor, organic matter and lime are generally added. If the soil is alkaline, only organic matter can be applied. For deep soil improvement, deep soil can be loosened by deep tillage or fertilization.

The soil is too sandy or sticky: In addition to selecting crops or varieties that can adapt to this bad soil, foreign soil can be used to cover and apply organic matter to improve the sandy or sticky soil base. The soil in Taisha has poor water and fertilizer conservation, and organic matter can change this situation. Too sticky soil has poor porosity. When wet, it is like mud, and when dry, it is like stone. Organic matter can form granular structure and increase pores, which is beneficial to the intake or discharge of water. Exotic soil can make more use of topsoil when building houses.

4. Unbalanced soil nutrients

1. Judging the imbalance of nutrients: The imbalance of nutrients in the soil is invisible to the naked eye, which can be observed through the symptoms of plants, and can also be known through phytochemical analysis combined with soil analysis and diagnosis. Soil should also be analyzed and diagnosed regularly, which is as important as physical examination, especially intensive cultivation, at least once every three or four years. Sampling for analysis and diagnosis of problematic soil or plants should select soil or plants that are representative of the problem, and it is best to select soil or plants that are not problematic next door or nearby, which will enable diagnostic experts to quickly find the problem.

2. Solution to soil nutrient imbalance: Understand the characteristics of crop varieties: Because various crops have different nutritional needs for soil, surgery can be taken after diagnosis of symptoms, and those lacking nutrients can be supplemented by emergency foliage, thus improving the root cause of soil fertilization. For example, people who are not suitable for acid and alkali can adjust and balance nutrient absorption. If it is caused by overnutrition and imbalance, it will take a long time to improve. Organic matter with high maturity (such as various composts) can be applied for adsorption, so as to reduce excessive harm and control it in balance.

Cooperative rotation system: unbalanced soil nutrition. Different rotation crops can absorb a lot of nutrients to reduce the damage to the soil, or the dry field and paddy field rotation system can achieve a state of nutrient balance, and with appropriate fertilization, the imbalance of soil nutrients can be improved.

Verb (abbreviation of verb) accumulation and pollution of salt and heavy metals

1. Judging the accumulation of salt and heavy metal pollution: The most accurate thing is to determine the salt and heavy metal content through chemical analysis. Others can also be measured by conductivity meter. When the conductivity is high, the growth of most crops will be hindered. The accumulation of salt can be observed with the naked eye. In the process of diagnosis, white powder or crystalline salt can be observed from the sun-dried topsoil. If too much salt is accumulated, white matter will appear, and many vegetables will definitely not grow well. In addition, we should pay attention to the irrigation water source in order to observe whether the irrigation water is polluted by the factory.

2. Solve salt accumulation and heavy metal pollution: due to the accumulation caused by intensive cultivation of crops, a large amount of salt fertilizer can be used in dry field and paddy field rotation, and a large amount of soluble salt can be washed away during paddy field cultivation; Or choose more salt-tolerant crops, because the salt tolerance of crops is different; The application of organic matter is also helpful for salt washing, because organic acids decomposed by organic matter can increase the solubility of salt. The accumulated pollution of heavy metals is not easy to be washed away or removed, and a small amount of pollution can be absorbed by organic matter, which can be reduced by dilution; If the pollution is serious, it is not suitable to plant food crops or feed crops to avoid pollution entering the food chain; If you want to plant, you need to carefully choose non-edible plants, such as forest plants and fiber-specific crops. Exotic soil can also solve the problem of salt or light heavy metal pollution, and reduce the harm of high concentration salt or heavy metal by diluting soil.

The intransitive verb topsoil loss

1. Judging topsoil loss: This is easy to judge. As long as you look at whether the water flowing out of the rain is turbid or turbid, you can know whether the topsoil is lost.

2. Solution of topsoil loss: Topsoil should be protected by covering or planting grass, especially planting grass in orchard is the most effective, and weeding is not needed in rainy season. On the surface, the grass will absorb the fertilizer applied competitively, but after the inhaled fertilizer is cut, covered or ploughed, the fertilizer will return to the soil, which is very helpful to the topsoil fertility of perennial fruit trees. Grass can also make rainwater penetrate into the soil layer, increase organic matter and loosen the soil, which has a good role in maintaining fertilizer.

Seven. Soil diseases and insect pests

1. Judging soil diseases and insect pests: To accurately understand the diseases caused by roots, special identification methods are needed. The cause of root death may be caused by biological or abiotic factors, and may also be caused by interaction. The harm of nematodes to the root system is easy to observe, and the root system will have swelling, swelling or tumor-like symptoms.

2. Solutions to soil diseases and insect pests: The treatment of soil diseases and insect pests includes chemical treatment, physical treatment (such as high temperature) and biological treatment. In addition, soil improvers can also improve the soil by chemical, physical, biological and other different ways, making it difficult for pests and diseases to reproduce or increase crop resistance, so as to control soil pests and diseases. For example, the application of calcareous materials can also improve pests and diseases after the soil is adjusted by acid; The application of organic matter can improve soil and reduce the occurrence of soil diseases, but it should be noted that compost must be decomposed.

Eight. Soil problems caused by continuous cropping

1. Judging the problem of continuous cropping: one or the same crop grows poorly after continuous cropping, and fertilization can't completely improve it, such as seedling withering and root rot. The growing point or new leaf is abnormal or does not stretch.

2. Solution to the problem soil of continuous cropping: Crops that often have problem soil are not suitable for continuous cropping, and rotation has many benefits. In addition to planting other crops in the problem soil of continuous cropping, calcareous materials can also be applied to acid soil to improve acidification or improve soil microbial environment; The application of organic fertilizer can improve, organic matter absorbs toxic substances and decomposes toxic substances. Organic fertilizer is a total nutrient fertilizer, which can reduce the imbalance of nutrients. Biological balance can also be achieved by applying beneficial microorganisms. In addition, change the soil environment (such as soaking, turning over the sun, etc. ) It can also prevent some continuous cropping problems. Continuous cropping fields often have a large number of aboveground or underground roots, and these residues may also be the root of the problem. Therefore, clearing the residue in the field can reduce the harm of toxic substances or pests and diseases.

In short, not all of the eight common problems mentioned above exist in soil. Therefore, we should first judge what problems may exist from the soil we cultivate, and then solve these bottlenecks that endanger soil fertility. Soil fertility or fertility will naturally change, and soil productivity can be improved.