О ЦЕЛЕСООБРАЗНОСТИ ИЗМЕНЕНИЯ КОНЦЕПЦИИ ТЕХНОЛОГИИ ОБРАБОТКИ ПОЧВЫ
Конищев А.А.
Кандидат технических наук, Ивановский научно-исследовательский институт сельского хозяйства
О ЦЕЛЕСООБРАЗНОСТИ ИЗМЕНЕНИЯ КОНЦЕПЦИИ ТЕХНОЛОГИИ ОБРАБОТКИ ПОЧВЫ
Аннотация
Действующая концепция «послойно-плоскостного» построения операций обработки почвы имеет много технологических недостатков, вызывающих сомнения в целесообразности ее дальнейшего применения. Предложена новая концепция построения операций.
Ключевые слова: обработка почвы, плотность, погодные условия, урожайность
Konishchev A.А.
PhD in Engineering, Ivanovo Research Institute of Agriculture
ABOUT THE FEASIBILITY OF CHANGING THE CONCEPT OF TECHNOLOGIES OF PROCESSING OF SOIL
Abstract
The current concept of "layerwise - uniform in area" tillage has many technological shortcomings, raising doubts in the expediency of its further application. The new concept of operations is proposed.
Keywords: tillage, density, weather conditions, yield
Now worldwide technology of processing of soil for grain crops moving towards minimization of impact on the soil. The main reasons for this are three:
- The dependence of the low productivity of crops from the soil. Respectively of 0.1-17% (at vast impact 2.5-6%), while the effect of fertilizers within 17-57%, weather conditions – 31-72%.
- Inadequately high expenditure of time and energy to the implementation of the classical tillage in comparison with the recoil.
- Systematically increasing technological expenses (cost of equipment, fuels and lubricants, chemicals, wages), which press the farmers to look for the ways of cost reduction.
Taking into account the first two reasons and the fact that there are practically no operations in crops cultivation technology, the refusal of which (or their minimization) will have little influence on plants productivity, preference is given to economy by means of tillage.
As a result, the vector of minimization is aimed at decreasing of depth and intensity of tillage up to a full refusal of cultivation (No-till technology).
What changes with decreasing of tillage depth and intensity (see fig.)? First of all, a larger volume of soil remains (at best case) at a steady state below the level of seed covering, and often it has an excess density due to the impact of running systems of units. So, plants are to develop on soil with a density higher than optimal.
Fig. 1 - The change in the density of addition of soil in vertical section at various processing technologies
At the same time, many soil scientists’ researches show that with increasing of soil moisture aeration porosity should also increase for the normal plants development. With decreasing of the moisture, plants are more productive on compacted soil (better capillary pulling up of moisture). Accordingly, bulk weight (bulk density) of the soil (which the porosity directly depends on) must be lower at high humidity and higher at lack of moisture. So, not just a certain amount of soil density is important for the plants productivity, but the ratio of density and moisture regime.
Therefore, the cultivation of plants on soil with a high density provides an increase of yield in the case of lack of moisture and leads to reduction in yields in the case of sufficient or excessive (even temporary) moisture. So, the transition to minimum tillage "orients the crop" for its growing in the conditions of insufficient moisture.
The next question which is the subject of farmers’ interest is the following: what will the meteorological conditions be like the next agricultural year? After all, they need to plan and carry out the tillage before planting, i.e. before the next year starts! The weather service cannot help to answer this question, as the credibility of long-term forecasts is still rather low. So it is impossible to set a particular density of the plow layer in advance. Besides the weather conditions are very dynamic, and the change of soil bulk density during the growth process is impossible.
As a result, from a theoretical point of view, knowledge is: what density should the soil have in different moisture conditions; however, it is almost impossible to use them, because future is uncertain. Therefore, farmers work the soil basing on previous years, their own experience and traditions of a region. Nowadays the received yield (from a mathematical point of view) is random value depending on combination optimality "density of arable layer – mode of its moisture". It decreases business attractiveness in the sphere of crop production.
Dependence of agriculture on the current weather conditions becomes even more relevant in light of predicted global climate change. Some manifestations of this process are already recorded. For example, frequency of adverse conditions (drought, overwatering) is increased and transitions between them become sharper.
However, the commonly used concept of layer-by-layer tillage technology does not give a solution to this problem. According to this concept, for every operation, the soil is treated evenly over the area at a certain depth. First, when plowing, the depth is of maximum (accepted or possible).
Then, by the cycle of pre-sowing treatments, the top layer of soil is brought to the required quality for sowing.
And, finally, crop is seeded (it should be taken into account that sowing is its treatment on depth of seeds covering from the point of view of the soil). However, with every subsequent operation which is executable at a lesser depth, the results of previous tillage "are destroyed" (earlier loosened deeper soil layers are compacted by undercarriages).This sequence of operations under the scheme a "deep - smaller - very finely" was born simultaneously with the invention of the plow (tool). Another sequence is not allowed. Later the tools spading the soil without soil overturning were begun to be actively used. They made a change in the sequence of technological operations, but it was affected by the inertia of thinking. These tools were embed in the traditional sequence of operations. As a result, the concept of the "layerwise uniform in area" forming technologies of soil treatment took a global form, and the industry received a global problem in the form of soil overconsolidation by the aggregates.
The tractors are considered as the reason of this problem. It is solved by reducing the impact of tractors on the soil. However it can be seen from the given analysis that the problem not only in tractors.
It is necessary to make several changes in the current concept of soil treatment technologies to solve the abovementioned problems [1,2].
- We must abandon the uniform treatment of the entire area of the field. It is proposed to form adjacent plots of a certain size with the soil density propitious for lack of rainfall (compacted plots) and precipitation excess (loose plots). The mutual influence and addition of plots with each other will reduce the dependence of crops on the current weather conditions and thereby increase their productivity.
The size of the plots should depend on the climatic characteristics of the region applying the technology. The more precipitation, the greater the size of the loose plots must be, and vice versa. In such a way the soil treatment can be adapted to any region of application. Moreover, if the natural soil density in the region of technology application is equal to the required density of one of the plots, you can switch to the combination "treated area – not treated area". As a result, it is possible to obtain additional savings resources (for example, cultivation of only loose plots on soils with high equilibrium density). And it is necessary to cultivate the plots that require firming on naturally loose soils. In this case, it should not be loosened, as it is done nowadays, but conversely – to be firmed!
The inclusion of agrophysical properties of the soil in the composition of the factors which influence plant productivity, will allow eliminating dependence of crops on upcoming weather conditions with a simultaneous share increase of treatment effect on yield and also giving the direction for treatment improving in the case of a possible climate change.
In addition, the usage of a combination «treated area – not treated area" leads to treatment minimization. Only the preconditions of such a minimization are fundamentally different from current ones. Nowadays the minimization is based solely on economic factors (the desire to reduce the costs for treatment). In the proposed variant the resulting savings are secondary! The first place is given to the optimization of conditions of plant development and soil conditions of the region.
- To implement the first condition, deep loosening of soil should be performed simultaneously with sowing; because any preliminary formation of variously compacted soil areas will lead to their subsequent damage. Compaction of the plow layer occurs at 60-70% in single pass of a tractor. So, the tractor of a sowing unit almost reduces the efforts to create differently compacting areas to zero.
The combination of tillage and sowing at the same time allows completely eliminating soil overcompaction by tractors and generating the plots of required density. It also saves the labor effort at the stage "tillage – sowing".
The subsequent soil compaction occurring during the crops treatment by herbicides has almost no effect on yield.
Conclusion: The given analysis confirms the presence of positives sides in the change of concept of soil treatment technologies.
References
- Konishchev A.A. Method of soil treatment // Patent RU № 2453091. 2012. Bul.№17
- Konishchev A.A., Konysheva E. N. Tillage-sowing complex // Patent RU No 2289232. 2006. Bul.№35