Tillage: Eradicate weeds and volunteer cereals through stubble cultivation
Loose, clump-free, crumbly and reconsolidated – these are the optimum characteristics of cultivated soils. Tillage is becoming increasingly important in achieving this, particularly in view of fertiliser regulations and the restricted use of plant protection products. The main options for tilling are stubble cultivation, primary tillage and seedbed preparation. In general, as with all field work but especially tillage, it is important to avoid damage from soil compaction. In this context, stubble cultivation becomes highly significant.
Goals of stubble cultivation
The primary goal of stubble cultivation is to reduce the amount of residual seeds in the soil, and to encourage weed seeds and volunteer cereals to germinate by incorporating them just below the surface. This involves incorporating the organic matter into the soil at a shallow depth and disrupting capillary action in the soil, which prevents rising water from evaporating. It usually requires at least two passes. The first pass is shallow and the second is at a medium depth, which enables the crop residues to be distributed within the soil. To optimise the mixing effect and to break up tyre tracks, it is recommended to work at a 15-degree angle to the direction of the stubble during cultivation (around two threshing widths). The timing of stubble cultivation is highly weather-dependent. There should ideally be no rainfall between the first, very shallow cultivation pass and the following, deeper cultivation pass. If the cultivator is set too deep during the first pass, the incorporated soil horizon can dry out, causing the opposite effect. On the other hand, to retain as much ground water as possible, the ground should be tilled promptly after harvesting.
Any residual seeds from weeds or the previous crop can be eradicated either mechanically or chemically before sowing the next crop. This requires them to germinate evenly. Shallow cultivation has additional positive effects, such promoting a crumbly, well-consolidated soil texture. When controlling weeds and unwanted plants mechanically, the weather should be dry – including on the subsequent days – to prevent the plants that are pulled out from continuing to grow. Controlling some particular weeds, however, requires multiple passes of deep cultivation to bring their subterranean rhizomes up to the surface. Tillage encourages the organic matter in the soil to rot. By mixing soil into the crop residues, it facilitates their conversion, which prevents pathogens from being transferred to the new crop.
Image by Saftladen on Pixabay
Stubble cultivation process
During the first pass of stubble cultivation, the soil underneath the stubble should be broken at the shallowest depth possible (max. 5 cm) to avoid fallen seeds from volunteer cereals and weeds from penetrating the deeper soil layers where they cannot fully germinate. Furthermore, cultivating the deeper soil layers consumes more energy because a larger volume of earth needs to be shifted. To sufficiently capture root-propagated and germinated weeds, the soil should be cultivated at maximum width. Wing share cultivators or disc harrows are well suited to this. Seven to ten days after the first pass of stubble cultivation, a second should follow depending on the weather. During the second pass, a working depth of 10–12 cm should be maintained. On compressed areas of soil, the working depth should be adjusted as necessary.
The tools available for shallow stubble cultivation are duckfoot shares and discs (serrated or smooth). Narrow line spacing is advantageous. Wing shares, on the other hand, are primarily used for deeper cultivation. An important criterion for successful stubble cultivation is the harvesting quality of the previous crop. If the straw is poorly distributed or the stubble is too long, this can have a negative effect on stubble cultivation. On the other hand, to accelerate microbial degradation, the straw needs to be chopped at a shorter length and with a higher degree of splicing. This requires the use of a well-maintained set of knives on the harvester.
How the seedbed is then prepared for seed sowing all depends on the subsequent crop that is to be grown. If the seeds are small and require minimal energy for germination, such as sugar beet or oilseed rape, it is best to prepare a shallow seedbed with a fine texture. Whereas for cereals with larger seeds that require more energy to germinate, a deeper seedbed should be prepared.
Tilling with 365FarmNet
ActiveDoc is part of the 365Active System. ActiveDoc enables each work process from tillage to harvest to be recorded and analysed, regardless of the crop being cultivated.
Mit LACOS Fahrspurplanung die optimalen Routen für Ihre Schläge anlegen – auch ohne automatisches Lenksystem.
AgroPressure by Michelin
AgroPressure by Michelin is a free component that can be used to calculate the optimum tyre pressure for avoiding soil compaction.