Information

Components of an adaptive landscape farming system

Components of an adaptive landscape farming system


Read part 1: What is adaptive landscape farming

All those who wish to master adaptive landscape agriculture (abbreviated as ALZ), need to develop the following main stages:

1. Collect background information to optimize the land use area. As a result of the work, the information collected should give a specific answer: what soil fertility exists at the moment, not in general, but specifically on each bed; what measures should be taken, if it is low, for its reproduction; what amount of agricultural products a given summer cottage or farm plot can produce.

2. Draw up a production program for the planned crop production.

Consistently, from the determination of the maximums limited by nature (soil, climate, plants, animals), with a gradual transition to the realities associated with the current state of affairs and the forecast of its material, technical, financial and staffing in the future, the yield and production volumes of vegetables are determined, berries and fruits at a specific farm or summer cottage.


3. Conduct the design of an adaptive landscape farming system.

Crops and their varieties are selected, crop rotations are compiled, specific technologies for plant cultivation are developed that ensure the selected level of productivity, the required indicators of product quality are set in conditions of ensuring the sustainability of agricultural landscapes and agroecosystems. The design is carried out in the following sequence.

3.1. Design of adaptive landscape land management of the territory.

Currently, in our region, the land is used in many ways traditionally, by intuition or according to the previously established way. But with traditional land use, it is impossible to make the transition to adaptive landscape intensification of agricultural production. If in agricultural circulation there are lands that, due to their genetic characteristics and agrochemical state, should not be used in intensive farming, then it is useless to invest new funds in them, since the corresponding return may not be obtained.

Ideally suburban soil should be assessed in two categories:

  1. on ecological capacity and permissible anthropogenic load;
  2. by the degree of suitability for the cultivation of agricultural crops and, most importantly, by the size of the yield.

3.2. Designing the structure of sown areas and crop rotations.

The basis for the design of crop rotations should be based on the assessment of land in the two noted categories, taking into account the program of crop production.

3.3. Compilation of a fertilizer application subsystem.

Fertilizer application requires not only the cost of decent funds, but also literally a jewelry approach to each soil contour on the site. The times when fertilizers were poured quite generously are a thing of the past, now the moment has come for their economical and differentiated use. At the same time, the principle of advanced fertilization should be strictly implemented: they should be applied as little as possible, but as much as the plants need, and not at the request of the owner or not because of the owner's love for fertilizers. The subsystem is compiled on the basis of the received input detailed information about soil fertility and its supply with the necessary nutritional elements.

3.4. Plant protection subsystem. Plant protection is an integral part of ALZ. The situation in our time is difficult, because in most horticultures the plant protection system is violated, which led to severe infection pests and diseases sowing material, soil and environment, strong infestation of fields with harmful weeds. We cannot exclude the use of chemical plant protection products, since without them we cannot get a decent harvest without them.

Of course, you need to follow agricultural techniques, apply biological methods of plant protection. However, these methods alone cannot improve the phytosanitary situation, so the need for herbicides, pesticides and insecticides will always persist. Another thing is that they should be applied more carefully.

3.5. Soil processing subsystem. Tillage, being the main technological process in agriculture, is a system of techniques for optimizing the physical and biological conditions in the arable soil layer for physiologically normal growth and development of crops. When processing the soil, the ability of the soil to disintegrate into a lumpy structure is realized, which provides effective fertility, water resistance, porosity, mechanical strength, density, biological activity and biological stability, the optimal ratio between porosity and density, water retention capacity, thermal regime and gas exchange of the root system of plants with the atmosphere.

In addition to improving the physical, physicochemical, chemical and biological properties, the subsystem of soil cultivation ensures the cleansing of fields from weeds, pests and pathogens, and is also an element of soil protection systems for protecting soil from wind and water erosion.

3.6. Subsystem for the purchase of seeds, selection of varieties. Seeds and crop varieties are the most important condition for obtaining sustainable yields in ALZ. Sowing should be carried out only with seeds of excellent and good quality, corresponding to GOSTs, grown in optimal soil-climatic and agrotechnical conditions, dry, not affected by pests and diseases, with high germination energy.

Seed quality assessment has always been both challenging and relevant. Difficult because all information about this quality is hidden in the molecular and anatomical structures of seeds, and any methods are able to reveal it only partially, and it can fully manifest itself only at the end of the growing season of the plant that has grown from it.

3.7. Design of agrotechnical technologies. The central core of the projected ALZ is the choice of optimal technologies for the cultivation of agricultural crops.

Thus, as a result of the solution of this program in the technological design, all elements of the ALZ are finally concretized, including the soil cultivation system taking into account crop rotation, the fertilizer use system, the weed, pest and disease control system, the land reclamation systems, the systems of hydraulic engineering and irrigation and drainage measures are substantiated.

4. Conducting landscape farming in kind. The maintenance of ALZ means compliance with the developed complex of land management, cultural, technical, technological and information activities in a real situation and in real time.

Conventional farming systems have been shaped most by common sense. Common sense is good, but not enough to master a new system. To conduct adaptive landscape agriculture, it is necessary to have modern technical means of measuring in local agroecosystems of spatio-temporal inhomogeneities of the plant habitat. For this, fundamentally new methods of forecasting and managing the regime parameters of agricultural landscapes that affect the production process in agricultural fields should be applied.

Landscape agriculture requires the use of unmanned aerial and space methods of sensing the earth's surface, determining the soil fertility not only of the upper arable layer, but also of the land in deeper horizons. While little experience has been gained in using such tools, reliable instrumental meters and the corresponding algorithmic and software for them have not been fully developed. We hope that in the future they will all come to dacha farming.

Until then. We believe that the reader did not find this material very difficult, but do not despair, this is just the beginning. We hope that the main provisions outlined in the article are remembered, and later we will analyze everything once again in detail in relation to summer cottage agriculture in subsequent articles on the pages of the journal.

Continue reading: Devices and methods in an adaptive landscape farming system

Gennady Vasyaev, Associate Professor,
Chief Specialist of the North-West Scientific Center of the Russian Agricultural Academy,

Olga Vasyaeva, amateur gardener


Agroecosystem analysis [edit | edit code]

Agroecosystems analysis is a thorough analysis of the agricultural environment that considers issues of ecology, sociology, economics and politics with equal weight. There are many aspects of the analysis, but it is impossible to cover everything. In general, agro-ecosystem analysis can be used to determine the sustainability of an agricultural system. It is obvious, however, that the "stability" of the system depends to a large extent on the definition of stability chosen by the observer. Agroecosystem analysis is a tool of interdisciplinary science - agroecology. Agroecology and agroecosystem analysis are not the same as sustainable agriculture, although the use of agroecosystemic analysis can help a cropping system become viable. Agroecosystem analysis is not a new practice, farmers and farmers did so when society moved from hunting and gathering to food production. Every time a person engaged in agriculture assesses his position, determines the methods that best suit his interests, he performs an agroecosystem analysis.


Planting seedlings of peppers in the Urals in 2021: terms, favorable days

Growing any vegetables in regions with a harsh climate requires a lot of work, let alone such heat-loving crops as pepper. But thanks to the work of breeders, varieties and hybrids have appeared that give very good yields even in the Urals.

True, you will have to grow pepper seedlings, since otherwise the culture simply will not have time to bear fruit.

Ural gardeners grow peppers in greenhouses, under shelters (arches with a film or non-woven material), in greenhouses. In hot summer conditions, peppers grow well in the open field, but such seasons are rare in this area, and frosts can always come suddenly. Therefore, it is better not to take risks and grow plants indoors.


Natural farming in the garden - practice

Periodic, deep digging is not acceptable if your goal is organic farming in the country. Striving for perfect soil cultivation spoils the soil, backfires on it, making it heavy, dry, lifeless, hard as stone. As practice shows, this can be avoided using certain techniques:

  • divide the site into small beds, depending on the species composition of the plants that will be planted
  • try to cover the soil with natural, organic materials, since bare ground is unprotected, less barren
  • regularly mulch the soil to a depth of at least 10 cm, which will reduce the growth of weeds, protect plants from pests, exposure to ultraviolet radiation, and ensure long-term preservation of moisture in the ground.


DESIGN OF A FERTILIZER SYSTEM, CHEMICAL RECLAMATION AND REPRODUCTION OF SOIL ORGANIC SUBSTANCE

Analysis of the state of soil fertility in crop rotation fields and non-crop rotation areas. When analyzing the soil fertility of the crop rotation fields of the farm, for comparison, reference data on the provision of soils with mobile forms of phosphorus and exchangeable potassium are used (tab.

The optimal content of mobile phosphorus and exchangeable potassium in sod-podzolic and gray forest soils with an average yield of cereals, leguminous crops and grasses corresponds to the third and fourth classes of supply (100-150 mg / kg of soil), and with their high yield and for row crops - fifth grade (180-250 mg / kg).

Substantiation of simple or extended reproduction of soil fertility. At a low level of soil fertility, 63. Grouping of soils according to the content of mobile phosphorus and exchangeable potassium,

I can plan extended, and at high - simple reproduction.

Doses of fertilizers to achieve the planned level of the content of mobile phosphorus and exchangeable potassium in the soil are calculated by the formula

where D is the amount of fertilizers required to bring the content of P2O5 or K20 in the soil to the planned level, kg a.i. per 1 ha C] and C2 are the actual and planned (desired) content of P2O5 or K20 in the soil, mg / kg H is the dose of nutrients (P205 or K2O) required to increase their content in the soil by 1 mg / 100 g ( GO mg / kg).

Example. It is required to bring the content of mobile P2O5 in soddy-podzolic medium loamy soil to 120 mg / kg with its initial content of 60 mg / kg. In this case, in addition to the removal of phosphorus by plants, it is necessary to add for the crop rotation:

D = 0.1 (120 - 60) 70 = 420 kg / ha Р205.

The standard costs required to increase the content of P2Cgt5 and K20 in soils by 1 mg / 100 g (10 mg / kg) are shown in Table 64.

With the optimal content of mobile phosphorus and exchangeable potassium in the soil, the dose of fertilizers for the planned yield can be calculated only by the value of the economic removal of these nutrients. Compensation of phosphorus and potassium removal from the soil by fertilizers reliably maintains

created an optimal level at which neither yield nor soil fertility is reduced.

When changing the structure of sown areas or planning a significant change in the yield of agricultural crops in the crop rotation, the coefficients of recovery of the removal (KVV,%) are introduced and new doses of fertilizers (Dud) are calculated, based on the changed removal (B) of nutrients by plants and the desired coefficient of replacement of the removal:

With an expanded reproduction of soil fertility, the coefficient of replacement of removal, and, consequently, the intensity of the balance of phosphorus and potassium should be 120-140%. If there is an economic or ecological need to reduce the content of nutrients in the soil, a replacement coefficient of less than 100% is introduced, their balance in this case will be negative.

In the Non-Chernozem Zone, about 30% of arable land and 50% of other agricultural land are soils with a low P2O5 content (up to 50 mg / kg of soil). On these soils, it is impossible to sustainably obtain not only a high, but also an average yield. Therefore, the introduction of phosphorus fertilizers is a powerful factor in increasing the productivity of poorly cultivated soils.

Calculation of the accumulation of organic fertilizers in the farm and their distribution for crop rotation. There are several methods for calculating the yield of bedding manure.

The first way. Determine the amount of manure accumulated from one head of livestock, with further recalculation for all livestock (Table 65).

Second way. The amount of manure / f is calculated by multiplying the amount of feed K consumed and bedding Jan 2:

65. The amount of manure received per year from one animal when keeping

on a straw bed, t

240-220 220-200 200-180 Less than 180
Cattle 9-10 8-9 6-8 4-5
Horses 7-8 5-6 4-4,5 2,5-3
Pigs 2,25 1,75 1,5 1,0
Sheeps 1,00 0,90 0,6-0,8 0,4-0,5

Stall period duration, days

Kind of animal

Third way. Based on the fact that approximately one half of the dry matter of the feed is digested by animals, and the other goes into manure. All dry matter of the litter also goes into manure. Fresh manure contains 25% dry matter and 75% water, therefore the total amount of manure (N) is 4 times more than half of the dry matter of feed (K: 2), folded with dry bedding I:

Fourth way. The amount of manure is determined by multiplying the mass of the entire herd by 25.

The yield of litterless manure is determined as follows. With a stable herd structure and feeding animals a significant amount of concentrates, the annual manure yield is determined according to the standards for excrement output in different sex and age groups of animals, shown in Table 66.

66. The daily output of excrement in cattle with an average

The daily excrement yield from one laying hen is 170-190 g, turkey - 450, ducks - 420, goose - 600 g. The daily excrement yield from pigs is given below.

Age-sex group of animals Output per day, kg

Along with the accumulation of manure on the farm, it is possible to harvest peat, sapropel, accumulate poultry droppings, slurry, prepare composts, use straw, and green fertilizers. Since the dry matter content of these fertilizers is different, they can be converted to bedding manure for ease of use. In this case, conversion factors are used.

The conversion factors for organic fertilizers into bedding manure (according to Krylatov and Nemtsov) are given below.

volume of biological characteristics of crops. First of all, they plan to apply organic fertilizers for vegetables and row crops, then for winter cereals and corn. Moreover, it is advisable to use manure, composts, peat, bird droppings for vegetables and roots, tubers, and straw, green manure, sapropel, etc., can be used for grain crops.

The dose of organic fertilizers for crop rotation in terms of bedding manure is at least 20 t / ha. The positive effect of organic fertilizers appears within three years.

Calculation of the need for agricultural crops in fertilizers for the planned harvest using the calculation and balance method, Calculated

the balance method for determining fertilizer rates takes into account the removal of nutrients with the planned yield, the utilization rates of nitrogen, phosphorus, potassium from the soil and fertilizers.

The fertilizer dose (kg a.i. per 1 ha) is calculated by the formula

where Y is the yield, c / ra B is the removal of nutrients with the harvest, kg / c 3 is the stock of available forms of the nutrient in the soil, kg / ha, to determine it, the content of elements in mg per 100 g of soil (found by cartograms) is multiplied by 30 Kp - the utilization rate of the nutrient from the soil, which is found by dividing the percentage of use of this element from the soil by 100 Ku - the utilization rate of the nutrient from fertilizers (the percentage of use of this element from fertilizers is divided by 100).

Reference materials for calculating the doses of mineral fertilizers are presented in tables 67, 68.

67. Removal of nitrogen, phosphorus, potassium per 1 ton of marketable products by various

The use of nitrogen, phosphorus, potassium from fertilizers for all field crops on average for a rotation of crop rotation is: nitrogen 60-70%, phosphorus (P3O5) 30-40, potash (K2O) 70-80%.

1 ton of average quality manure contains: N - 3.3 kg, P2O5 - K2O - 2.6 kg. Good quality manure contains: N - 5 kg, P2O5 - 2.5, K2O - 5.5 kg. The use of nutrients from manure for the rotation of crop rotation is: nitrogen 50-55%, P2O5 - 40-50, K2O - 60-70%. The nutrient utilization rates of various crops from fertilizers are shown in Table 69.

The calculation of fertilizer doses for the planned yield of agricultural crops of the crop rotation is carried out in the following sequence. Determination of the removal of nutrients by the planned harvest (NPK removal by a unit of marketable product x yield), kg / ha. Calculation of NPK consumption by plants from soil (NPK content in soil, mg / 100 g x 30 x utilization factor), kg / ha.

* The coefficient of nitrogen fixation of grain legumes is 0.4-0.5.
Determination of the use of N by plants from the crop residues of the preceding leguminous crops (according to Table 70), kg / ha. Calculation of NPK consumption from manure taking into account its aftereffect (Table 69), kg / ha. Determination of NPK use by plants from mineral fertilizers applied for previous crops (Table 69), kg / ha. Calculation of the need for application of mineral fertilizers, taking into account the utilization factor in kg a.c. per 1 ha (removal with harvest - consumption from soil, crop residues of legumes, manure, mineral fertilizers applied in previous years): utilization rate. Determination of doses and forms of application of mineral fertilizers in physical mass, kg / ha (NPK requirement in a.i.: content of a.s. in fertilizers).

Correction of doses of mineral fertilizers is carried out in accordance with the requirements of the balance of nutrients for the crop rotation for soils of different degrees of cultivation (Table 71). The need for such an adjustment is mainly due to the wide

72. Doses and fertilizer requirements for crop rotation

kim variation of the coefficients of the use of nutrients from the soil and fertilizers by plants, depending on external factors.

Doses and fertilizer requirements for crop rotation are recorded in the form of table 72.

Drawing up a fertilizer application system. The doses of fertilizers for crops developed taking into account the weighted average soil fertility of crop rotations are distributed according to the methods of application and summarized for each crop rotation in the form of table 73.

73. The system of application of fertilizers in crop rotations and on natural forage lands (organic fertilizers - in physical mass, mineral - in the active substance)

The record of the farm's need for mineral fertilizers is made in the form of table 74.

Chemical soil reclamation. Phosphorization of soils. Phosphorization is considered to be such a method of using phosphate rock, in which at least 200 kg of P2O5 (phosphate rock) is applied per hectare at a time. Its main task is to improve the phosphate regime, which, in combination with other factors, ensures high stable crop yields. Along with this, soil acidity decreases, which creates more favorable conditions for cultivated plants and microorganisms.

The availability of phosphorus added to the soil to plants depends on the ratio between the mass of fertilizer and the mass of the soil, with which

second, phosphoric acid ions interact in the contact zone. On acidic soils, phosphorus fertilizers are bound into hard-to-reach compounds; when high doses are applied, their effectiveness increases. The optimal doses, calculated taking into account the payback of the application costs, are shown in Table 75.

Liming of acidic soils. Liming is an important prerequisite for increasing the yield and efficiency of mineral fertilizers. The need for systematic liming of soils in the Non-Chernozem zone is associated with a significant annual leaching of calcium (80-200 kg / ha) and magnesium (30-50 kg / ha) by precipitation and with an increase in the number of alienated bases with the crop when mineral fertilizers are applied. Soil acidity impairs the agrochemical, agrophysical and biological properties of the soil.

The high efficiency of mineral and organic fertilizers is achieved with a close to neutral reaction of the soil environment in the crop rotation, therefore liming should be ahead of the rate of application of fertilizers.

The dose of lime is determined by various methods. According to pHS0L, the degree of saturation of soils with exchange bases and the granulometric composition of the soil, using the reference material (Table 76). By hydrolytic acidity Нг, taking into account the type of lime fertilizers and the need for liming of soils:

CaCO3, t / ha = 1.5 Ng Ca (OH) 2gt t / ha = 1.1 Ng CaO, t / ha = 0.84 Ng. Using the standards of lime costs to reduce soil acidity by the required amount (Table 77). Doses of lime are determined by this method, if it is not required to completely neutralize the acidity of the soil when cultivating individual crops, but it is necessary to maintain the optimal pH value.

It has been experimentally established that to shift the reaction of the soil solution by 0.1 pH on sandy loamy sod-podzolic soils, it is enough to add 0.3 tons of lime per hectare, loamy - 0.4 -

Lime fertilizers are applied primarily for vegetables, fodder and sugar beets, annual and perennial legumes, corn, winter wheat, barley. It is most advisable to add a full dose of lime after harvesting the predecessor for the main soil cultivation. In crop rotations with perennial grasses (clover, alfalfa, sweet clover), liming is carried out under a cover crop, and in case of bare sowing, directly under perennial grasses. With a lack of lime, it is introduced fractionally for cultivation. Under potatoes and flax on strongly acidic soils, 1 / 2–3 / 4 doses of lime are applied.

Calculation of the balance of organic matter in the soils of the crop rotation. One of the most important indicators of soil fertility is the content of humus, the reserves of which are largely

Penalties determine the agrochemical, agrophysical and biological properties of the soil. In humus-rich soil, the availability of phosphorus to plants increases, the loss of nutrients from leaching decreases, the rate of decomposition of pesticides increases, and the costs of soil cultivation are reduced. The humus content depends on the soil and climatic conditions, the structure of the cultivated areas, the intensity of soil cultivation, the amount of fertilizers and ameliorants used. During agricultural use of soils, humus is continuously mineralized, and nutrients are alienated with the harvest. The greatest losses of humus due to its mineralization and erosion processes occur in steaming soil and under cultivated crops in comparison with grain crops and perennial grasses. Therefore, when developing an adaptive landscape farming system in crop rotation, it is necessary to calculate the humus balance.

The balance of humus in the soil can be deficit-free, when its arrival as a result of humification of fresh plant residues and organic fertilizers completely balances the consumption due to mineralization and soil erosion. The balance is considered positive when the arrival of newly formed humus exceeds its consumption, and negative when the arrival of humus does not compensate for its losses. The consumption of humus is calculated according to the intensity of its mineralization in specific conditions.

It has been established that in the Nonchernozem zone, on sandy and sandy loam soils under grain crops, 1.8-2.2% is mineralized annually, on loamy and clay soils - 1.0-1.2% of humus from the gross reserves. Under cultivated crops, the mineralization coefficients of soil organic matter are usually 2 times higher.

Annual losses of organic matter in peat during the cultivation of agricultural crops are (t / ha): perennial grasses - 2-4, cereals - 5-7, row crops - 9-11.

The approximate consumption of humus can also be calculated by the method proposed by IV Tyurin. It is based on the removal of nitrogen with the crop and the utilization rate of mineralized soil nitrogen by plants during the growing season. Since about 50-60% of nitrogen alienated with the harvest of the main and by-products falls on humus nitrogen (the rest is nitrogen of organic and mineral fertilizers, nitrogen supplied with precipitation, crop residues and due to nitrogen fixation), and the nitrogen utilization factor soil by plants is about 70%, you can determine the amount of mineralized humus, given that the proportion of nitrogen in it is 5% (1/20 part).

For example, the removal of humus nitrogen by the crop of winter wheat (50%) is 60 kg. Based on the fact that about 70% of soil nitrogen is used, the total amount of mineralized nitrogen is 60: 0.7 = 85 kg / ha, and the amount of mineralized humus is 1700 kg / ha (85 • 20). Humus mineralization coefficients in gray forest soils are approximately equal to 0.8-1.2%, in chernozems - 0.4-0.8%.

The arrival of humus in the soil is calculated based on the mass of stubble-root residues, applied organic fertilizers and the coefficients of humification of their organic matter.

Post-harvest plant residues Humification coefficient and organic fertilizers

Perennial legumes 0.25

Perennial grasses 0.20

Cereals and legumes crops 0.18-0.20

Annual grasses for hay 0.18-0.20

Annual herbs for green mass 0.12-0.15

Potatoes, root crops, vegetables 0.05-0.8

Cattle manure 0.20-0.25

Peat-manure compost 0.25

The amount of stubble-root residues depends on the yield, biological characteristics of agricultural crops and is determined by the mass of the main product, taking into account correction factors (Table 78).

Table 79 shows an example of calculating the humus balance of a sod-podzolic medium loamy soil in a 7-field crop rotation. Humus mineralization is determined by the removal of soil nitrogen by plants. In this case, the share of humus nitrogen in the crop is taken as 50%. For example, in field 1, the removal of nitrogen by barley (35 kg / ha) is 90 kg / ha, including 45 kg / ha of humus nitrogen. Taking into account the fact that only a part (70%) of mineralized humus nitrogen is used by plants, its total mineralization is: (45: 0.70) = 65 kg / ha. Multiplying this value by the coefficient of conversion of nitrogen into humus (20), we find that the loss of humus is equal to (65 • 20) = = 13 c / ha. Further, according to table 78, we find the amount of plant residues of barley. With a harvest of 35 c / ha, about 39 c / ha will remain in the soil. Multiplying the mass of barley stubble-root residues by the coefficient of their humification (0.20), we find that the arrival of the newly formed humus will be 8 c / ha.

Having carried out similar calculations for all crops of the crop rotation, the balance of humus (the difference between input and output) is determined by fields and in general for the rotation. In our example, the negative balance of humus averaged 5.3 c / ha, to cover which, taking into account the humification coefficient (0.25), it will be necessary to apply 2.2 tons of organic matter of manure per hectare, or 10.6 tons of litter manure in natural physical condition, since the content of organic matter in it is approximately 20% of the wet weight.

80. Calculation of the balance of humus (carbon) in crop rotations when applying high doses


According to numerous studies, to maintain the humus balance of soddy-podzolic soils of light granulometric composition, the supply of organic fertilizers should be 12-15 t / ha, medium and heavy loamy - 10-12 t / ha. In gray forest soils and chernozems, the maintenance of the organic matter content of the soil at the initial level (stabilization) is possible when the supply of manure is 8-10 and 6-8 t / ha, respectively. The systematic use of higher (lower) doses of organic fertilizers, which is necessary to maintain a deficit-free balance of humus in the soil, first leads to a noticeable increase (decrease) in its content, and then the humus content stabilizes at a new quantitative level.

The humus balance can be calculated according to the scheme in Table 80 and the normative data given in the text.

When calculating the removal of nitrogen with the crop, correction factors are introduced for the granulometric composition of the soil and the cultivated crop (Table 81).


Watch the video: Lect. No 4. Components of Farming System u0026 their Maintenance