How to check the quality of the soil, such as fertility, etc.?

What are the differences in the physical properties of particles of different sizes? An important aspect is the difference in specific surface area. Imagine in your mind a soil cube with an edge length of 1, for the sake of convenience, we can imagine it as being made up of 1 cube of sand, then the total surface area of this soil cube is 6.

So what if it was made of cubes of clay? The diameter of the clay is at least 1 25 of sand, so if you calculate, this soil cube is made up of at least 15,625 clay particles with a side length of 1 25, and the total surface area is 150, which is 25 times larger. This is only an ideal situation, in fact, due to the joints of soil minerals, when the minerals are weathered into fine clay particles, the clay particles become irregular, and thus give the clay particles a larger specific surface area.

A larger surface area means greater adsorption capacity, stronger water retention capacity and the ability to adsorb mineral elements. At the same time, due to the accumulation, the porosity and aeration of the soil will become lower - this is the story of the Zen master.

It is precisely because of these differences in properties that mud kneading gives us a simple way to determine the texture of the soil. For example, if you dig out a handful of soil, mix it with a little water, and pinch it for a long time to become a ball, and you can't touch it, and it will scatter when you touch it, which shows that the main component of the soil is the sand particles with coarse particles, small specific surface area, and weak adsorption capacity, which is sand. If it can be pinched into a ball, but it can't be kneaded into strips, it means that the ratio of silt and clay in the soil is good, and this kind of soil is generally loam.

If it can be kneaded into a ball or rolled into a strip, but this strip cannot be bent or formed into a ring, it means that the sand content is relatively low, but the clay content is still not enough, which is considered silty loam. If you can knead it into a ball or a strip, you can bend it into a ring, but the ring is full of cracks, then this is clay loam. If you can perfectly complete the three challenges of balls, bars, and rings, then you can judge it as clay.

The above indicators may not be correct, please verify. On this basis, we can make a rough assessment of the soil quality.

You can buy your own testing instrument for soil testing formulas, **in thousands to 10,000, and add high-end functions**. However, farmers can directly take samples and take them to the local soil and fertilizer station for testing, which is generally free (update: the township and county are generally free but there is no formal test report, and the city has a test report, but it is charged.)

Jiangxi's ** is 30 50 yuan an indicator, generally measuring five or six commonly used indicators). Therefore, soil testing is not a difficult task, and the general crop countries have fertilization standards after making soil testing formulas. There are a lot of crop formula data stored in the instrument I bought, and I can directly and quickly know how to formula fertilizer.

1.Pay attention to the input of organic fertilizer and bacterial fertilizer.

We know that the main role of organic fertilizer is to promote the nutrient uptake of soil fertilizer and increase soil organic matter. The main cause of soil compaction is the lack of soil organic matter. Increasing the application of organic fertilizer is an important step to improve soil compaction.

The main driving force for the formation of aggregate structure is the decomposition of organic matter in the soil to form humus, which is mainly driven by soil microorganisms, and the active substances of microorganisms can combine with organic matter in the soil to contribute to the water stability of the soil. Secondly, through the activities of microorganisms, the ion exchange frequency of soil aggregate structure can be increased, the relative quality of soil can be reduced, and the soil structure can be improved by increasing the contact rate between crops and soil organic matter. Microorganisms can form metabolism through life activities, effectively absorb the original harmful substances in the soil, form a new microbial system, and produce active substances that reduce pests and diseases.

At the same time, it is applied to crops, and to a certain extent, it regulates the nutrient absorption during the growth of crops.

2.Increase the use of humic acid fertilizers.

Humus is the main component of aggregate structure, and humus is mainly obtained by decomposing organic matter from soil micro-substances. Therefore, supplementing the soil with humic acid can increase the number of aggregate structures. This improves soil compaction.

3.Reduce the use of chemical fertilizers, organic fertilizers and chemical fertilizer mixtures.

The combination of organic fertilizer and chemical fertilizer can promote the absorption of nutrients from soil and chemical fertilizers, reduce soil residues, and prevent soil compaction caused by chemical residues in the soil. The main reason for soil compaction is the partial application of chemical fertilizers, ignoring the use of organic fertilizers, and carrying out formula fertilization on their own land. Such a scientific and reasonable fertilization method can not only reduce soil compaction, but also control the amount of blind fertilization, and there are many ways to increase the application of organic fertilizer, such as the application of crushed straw, farmhouse fertilizer, Hongtong organic fertilizer, etc. in the soil, and the application of Hongtong biological fertilizer is better.

Unreasonable water irrigation with drip irrigation and sprinkler irrigation measures is also an important cause of soil compaction. The implementation of sprinkler irrigation and drip irrigation facilities in the land can directly transport water to the roots of crops for absorption, which will not cause water waste and is also a good way to prevent soil compaction.

In fact, it is not difficult to judge soil fertilizer, and soil fertility can be judged mainly according to the following points.

According to the soil color: the loam soil is darker; Whereas the lean soil is light in color.

According to the depth of the soil layer: the soil layer is generally more than 60 cm; Whereas, lean soil is comparatively shallow.

According to the soil tillability: the loam soil layer is loose and easy to cultivate; The lean soil layer is clay and ploughed, and the cultivation is laborious.

According to the animal situation: there are snails, loaches, earthworms, large locusts, etc. There are small ants, large ants, etc., most of them are thin soil.

According to the plant conditions: the soil where red head sauce, goose hair grass, camellia grass, etc. are grown, and the soil is fertile; The soil where cow hair grass, duck tongue grass, triangular grass, wild orchids, wild onions, etc. are grown.

According to the fertilizer retention capacity: the soil with strong fertility, sufficient and long-term fertilizer supply, or potentially high fertility is considered fertile soil.

According to the slurry properties and cracks of the soil: the fertile soil is not easy to slurry, and the soil cracks are many and small; The lean soil is very easy to slurry, easy to compact, and the soil cracks are few and large.

According to the water retention capacity of the soil: the water infiltration is slow, and the irrigation can be maintained for 6 to 7 days for the fertile land; Thin soil that does not infiltrate or infiltrates quickly along cracks.

According to the water quality: the water is slippery, sticky to the feet, and the sun or feet are blistering when they are blistering for the fertile soil; The water quality is light and colorless, and the paddy field does not bubble, or the bubbles are small and easy to disperse.

The main difference between soil environmental quality and soil fertility quality is that they differ in their focus and focus.

1.Soil environmental quality is mainly concerned with the content of harmful substances in the soil, such as heavy metals, pesticides, etc., which may not only have an impact on humans and the environment, but also affect the ecosystem function of the soil and lead to soil pollution.

2.Soil fertility quality is more concerned with the nutrient content, organic matter content and microbial quantity in the soil. These indicators are closely related to soil fertility and productivity, and directly affect the growth and yield of plants.

In short, although there is an intersection between soil environmental quality and soil fertility quality, the emphasis is different, one pays more attention to harmful substances, and the other pays more attention to fertility.

Soil environmental quality mainly focuses on the content of harmful substances in the soil, while soil fertility quality focuses on the nutrient content in the soil.

1. The content of soil environment is mainly concerned about the content of harmful substances in the soil, such as heavy metals, pesticides, etc., on human beings and the environment, which will affect the ecosystem function of the soil and lead to soil pollution.

2. The quality of soil fertility focuses on the nutrient content, organic matter content and microbial quantity in the soil, which are closely related to the fertility and productivity of the soil.

A: Soil fertility is an essential characteristic of soil. The soil contains almost all the nutrients needed by the crops, but they cannot be absorbed by the crops, and only the nutrients dissolved in the soil solution can be absorbed by the crops.

The ability of the soil to provide and coordinate nutrients and environmental conditions for the normal growth of crops is called soil fertility. In formula fertilization, it is first necessary to understand the size of the soil's fertilizer supply capacity. Because soil fertility is a comprehensive manifestation of soil physical, chemical, biological and environmental factors, it is not possible to express the fertility level of soil with exact quantitative indicators, let alone summarize soil fertility with the number of one or several factors, so the yield obtained by crop species on the soil without any fertilizer is usually taken as a comprehensive index of soil fertility.

Generally speaking, the high yield of blank indicates that the soil has strong fertilizer supply capacity and high fertility. On the contrary, the soil fertilizer supply capacity is weak and the fertility is low.

Chemical analysis method: determination of soil organic matter, nitrogen, phosphorus, potassium and other nutrients, this does not need to be detailed, it is estimated that you can not do it at home, you need to send it out for testing, can be tested by various counties and cities of soil and fertilizer stations, the Academy of Agricultural Sciences, and agricultural colleges and universities.

Observation method: mainly observe the color of the soil layer of 0-20cm, the color is generally gray or black, the content of soil organic matter is relatively high, and the soil is more fertile; Also look at the tightness of the soil, 0-20cm soil is generally granular, loose soil is more fertile; Finally, look at the biological condition of the soil, mainly to see if there are earthworms, the more earthworms, the more fertile the soil.

If there is a condition, the soil testing formula, not on their own judgment: perennial only the use of chemical fertilizer, no organic fertilizer will cause barrenness, depending on the degree of porosity, the soil fertile air permeability will be very good! In addition, apply more organic fertilizer, whether the fertilizer is fertile or not, can improve the soil fertility!

The easiest thing is to see how the crops on it grow.

Or take the soil sample to the testing station for testing.

Soil is composed of three substances: solid, liquid, and gas, and is called soil three-phase. Solid matter includes soil minerals, organic matter and microorganisms; Liquid matter mainly refers to soil moisture; Gases are the air present in the pores of the soil. These three types of substances in the soil constitute a contradictory unity.

They are interconnected, mutually restrictive, provide the necessary living conditions for crops, and are the ridge and material basis of soil fertility.

Fertile soil is the basis for crop production. The quality of the soil mainly depends on the fertility of the soil. Soil fertility is made up of three indispensable components: physical, chemical, and biological. Microorganisms are at the heart of soil biofertility.

Soil minerals are mineral particles of the same size formed by weathering rocks, such as sand grains, soil grains, gums, etc. Soil minerals are diverse and chemically complex. It directly affects the physical and chemical properties of the soil. It is important for crop nutrients**.

The amount of organic matter is an important indicator of soil fertility, and it is tightly bound to minerals. Generally, the organic matter content of cultivated land only accounts for the weight of the soil, and even less below the cultivated layer, but it has a great effect. Soils with a lot of organic matter are often referred to as "oily soils".

Soil organic matter is divided into fresh organic matter, semi-decomposed organic matter and humus according to the degree of its decomposition.

The following can be used to test whether the soil quality is compliant.

Test items] 1. Conventional indicators: pH, total salt amount, chloride ions, nitrate nitrogen, ammonium nitrogen, nitrite nitrogen, etc.

2. Heavy metal pollution: lead, arsenic, cadmium, chromium, mercury, nickel, copper, zinc, etc.

3. Trace elements: available iron, available manganese, available copper, available zinc, available silicon, available sulfur, exchangeable calcium, exchangeable magnesium, exchangeable potassium, exchangeable sodium, etc.

4. Fertility index: organic matter, organic carbon, total nitrogen, total phosphorus, total potassium, hydrolyzable nitrogen, available phosphorus, available potassium, etc.

5. Organic pollutants: mineral oil, volatile phenols, benzo(a)pyrene, total petroleum hydrocarbons, polychlorinated biphenyls, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCS), dioxins.

6. Pesticide residues: 66.

6. DDT, glyphosate, dichlorvos, phosphine, phosphine, atrazine, simazine, hexachlorobenzene, heptachlorochloride, aldrin, heptachlorochlorohydrate, endosulfan I, dieldrin, endrin, etc.

7. Applicable to soil analysis of farmland, vegetable land, tea garden, orchard, pasture, woodland, nature reserve and other places: nutrient analysis and soil pollution analysis.