Profile of fertilization and deep soil tillage

On many plots of land, compaction seriously deteriorates the fertility and production capabilities of soil. It hinders full exploitation of the genetic potential of the individual varieties and reduces efficiency of the inputs in the production process of the crops being grown, particularly that of organic and mineral fertilization. Finding a solution to this serious issue of soil compaction is now a hot topic in crop farming. Agricultural enterprises should therefore pay more attention to this issue. One possibility of restoring the soil structure is deep cultivation. For this ‘oil treatment’ BEDNAR FMT offers the TERRALAND chisel plough, which allows farmers to do more than just with a regular plough – they can use it for profile fertilization.

Application of fertilizer into the soil profile

One efficient way of maintaining a sufficient and harmonically balanced stock of nutrients in soil, not only in the plough layer horizon, but also in deeper layers of the soil profile, is the so called ‘profile fertilization’ system. This innovative way of fertilizer application, in combination with deep soil tillage, is suitable not only because it replenishes deficient nutrients in soil so as to achieve a harmonic level of adequate stock, but also because it improves accessibility of nutrients to the crops and has a positive impact on the growth of the root system. This method of fertilizer application and determination of the individual doses of nutrients for fertilization shall always be applied based on diagnostics of the stock of acceptable nutrients in the soil.

Placement of fertilizer at two levels (zones) of the soil profile provides continuous nutrition to the crops throughout the vegetation period. The main part of the fertilizer dose is placed into a deeper layer of the soil profile (depending on the crop and soil conditions to a depth of 15 to 25cm) in advance during primary soil tillage. The remaining part of the total fertilizer dose required based on the overall diagnostics (up to the maximum dose of phosphorus depending on the crops 40 – 50 kg P2O5/ha) is placed in a shallower layer under the seed bed shortly before seeding, or more precisely directly during seeding (the system of “under heel” fertilizer placement).

Application of granular fertilizers all over the area and their subsequent ploughing in on the surface negatively increases concentration of nutrients (salts) in the surface layer of the soil.This method of alternative placement of fertilizer into the soil profile before seeding has a negative impact on extension growth of the roots and hinders development of the entire root system architecture.

Impact of profile fertilization on the root architecture

Placement of fertilizer into the soil profile has a positive and stimulating effect on development of optimal root system architecture. An optimal and faster extension growth of the main primary roots provides for subsequent growth of secondary lateral roots and ensures widely spread and fine root hair even in deeper soil layers. With the current weather fluctuations during the vegetation period of the crops, a root system architecture of the crops that is developed in a timely and optimal manner, especially due to a longer extension growth of primary roots, delivers an increased tolerance towards periodic spells of drought (suitable also for ‘rain shadow’ areas). In extreme vegetation periods, the profile fertilization system helps to eliminate the impacts of drought on crop production. Application of deficient nutrients into the soil profile in order to provide nutrition to subsequent crops also partially increases their stock in the soil and enhances the absorption capacity of soils from the forms of nutrients (K+, Ca2+, Mg2+) which improves and stabilizes soil fertility in the subsequent season.

Ploughing fertilizers in, after they have been spread over the entire area, often results in mixing the fertilizers with soil which leads to their shallow placement in the profile and negatively increases concentration of nutrients (salts) in the top soil layer. This method of alternative placement of fertilizers into the profile before seeding has a negative impact on extension growth of the roots and hinders development of the architecture of the entire root system which, as a result, does not provide enough nutrition to the above-ground part of the crops and due to the shallow rooting, the crops are more susceptible to impacts on its growth during spells of drought.

When an ensuing system of fertilizer placement by the seed drill under the seed bed is used, application of fertilizer deeper into the soil profile (under heel fertilization) ensures continuous nutrition for young crops (maize, rape, sugar beet) which then show increased capabilities of nutrient intake.

Impact of profile fertilization on the root system architecture, field test in Rychnov nad Kněžnou – oilseed rape. Crops on land where the TERRALAND chisel plough was used and fertilizer was applied into the soil profile (25cm) with a thick crown of the globular root reaching approx. 30cm deep (left). The root system of crops on land which was ploughed showed a thinner root crown and the system architecture was shallow with poor lateral root hair (right).

TERRALAND TN 3000 HD7R chisel plough and FERTI-BOX FB 2000 F front container with a volume of 2,000L – a set designed for deep soil cultivation and for the application of fertiliser into the soil profile.

Disruption of the plough base and compaction

With repeated tillage of the soil profile to the same depth, either by ploughing or by minimization, the so called plough base is produced. In its proximity, the soil profile is more susceptible to undesired compaction due to operation of heavy machinery. This, in interaction with current extreme weather conditions, has a very negative impact on physical properties of the soil – porosity and penetration resistance. Deterioration of these properties has a negative impact especially on the speed with which the roots develop and the root hair is created. In compacted soils, the most seriously affected crops are those that produce yield by underground organs. E.g. in the case of sugar beet the tubers branch, in the case of potatoes the tubers are deformed. In cases of crops that produce a taproot – rape, soya or sunflower – its growth is hindered because the root cannot penetrate through the compacted subsoil and gets deformed. We cannot forget to mention barley which does not like permanently wet conditions that occur due to the fact that the plough base is created. In order to restore the soil structure and water regime, such plough base needs to be disrupted first. One solution is to use the BEDNAR TERRALAND plough chisel with which you can process soil intensively and disrupt compaction even in deeper soil profile layers. To fix compacted soils, you need more than one season, but even after the first year you can see improvements, e.g. better absorption of rain water or increased yield.

TERRALAND TO 6000 chisel plough and FERTI-BOX FB 3000 container for the rear hitch with a volume of 3,000L – a set designed for high daily outputs in deep soil cultivation and for the application of fertiliser into the soil profile.

TERRALAND TN 3000 HD7R chisel plough and FERTI-BOX FB 1500 TN carried container with a volume of 1,500L – a set designed for smaller farms for deep soil cultivation and for the application of fertiliser into the soil profile. The container may be part of a newly produced chisel plough, or it can be connected to older models.