Mulch

When mulching ( Middle High German mul, crumbling earth ',' dust ', see Mull ) is used in horticulture and agriculture refers to the small - or large-area covering the soil with unverrotteten organic materials ( mulch ). When mulching in agriculture or in landscape maintenance and horticultural larger areas are also referred to the mowing with simultaneous crushing of the mulch material by sickle or flail mower.

Origin and meaning of the word

The nowadays used word " mulch " is a contemporary borrowing (late 20th century) from English ( mulch, unverrottetes organic material ').

However, there is also an occupied since the 16th century adjective mulsch that in some Upper German dialects, rotten ',' soft ' means (even in the form of mölsch, molsch, melsch ). The root word is " grind " on the same root as and "mild " due (see f1griechisch malakos ' soft ', Hitt. Malisku, weak ', ' easy ', ' insignificant ').

The LSP definition of mulch is " land cover to promote the Gare ".

Mulching in horticulture

Mulching is an important technique in the context of the series as well as mixed culture of permaculture.

In horticulture, mulching refers to a special method that is used in the garden, in parks and in the fruit and vegetable production. The open ground between vegetable plants, flowers, shrubs and trees is here with lawn clippings, leaves, foliage and the like covered.

Function

• Protection: mulch keeps the soil cooler longer when exposed to heat, and it gets longer in the evening the days heat. Thus, the growing season is prolonged. Also, the loss of moisture of the soil is reduced. In heavy rain is through the mulch layer, the capping and washing out of the soil, prevents wind erosion.

• Närstoffeintrag: In addition to its protective function, the mulch layer will gradually be composted and the resulting humus acts as an organic fertilizer. Earthworms and other small creatures bring the mulch material into deeper soil layers and convert it into valuable plant food. It is important for this, as in any composting, a balanced C / N ratio, see below.

• Weed resistance: Due to the low incidence of light on the ground weed growth is slowed down on the area covered, but not always prevented.

Material

Starting from the soil, the planting, the availability and the desired mulching function selects one of the right material. If the mulch away at the cucumber sowing again, the carbon / nitrogen ratio is, for example, do not care. Mulch on a playground should be soft, but not dissolve so quickly.

• Green section: stickstoffhaltig, feuches material may rot easily combined with carbonaceous material such as straw, leaves. Weeds and plant residues can contain unwanted seeds or fungi.
• Manure, compost: nitrogen-, to mix. Mature compost is actually no more mulch, it is finished humus.
• Straw, leaves: kohlenstoffhältig, pure for shrubs and trees. Straw may like pesticides contain leaves from the street may contain heavy metals.
• Bark: kohlenstoffhältig. In perennial beds and shrubs are employed also bark mulch from shredded bark of conifers, mostly spruces. The material should be sufficiently long, i.e., be deposited at least three months, to ensure that the phytotoxic active ingredients of the bark of the tree, and resin such as tannin and tannins have been removed.
• Sawdust: kohlenstoffhältig very difficult decomposable
• Natural inorganic material: gravel or crushed stone is va for paths. Stone dust and lime is only for fertilization.
• Artificial material: In vegetable crops and pot and container plants are used - in the figurative sense of the cover - bioplastics and various types of plastic films for mulching. Moisture loss is very small, the soil is also hardly ventilated. Black slides allow the heating by the sun. Nonwovens offer more air circulation, but are translucent.

C / N ratio

Remains of mulch on the bed, it is decomposed and thus serves as fertilizer. In the selection of materials while a balance of carbon and nitrogen (C / N ratio) is important to ensure. For example, bark mulch. it is important to carry out a balancing nitrogen fertilization before application. This need is based on the following processes: nitrogen is a major nutrient for plants. Bark is rich in carbon and low in nitrogen and it is difficult decomposable. Therefore, consume soil organisms in the initial phase itself much nitrogen available from the few to break down the mulch. They build it into their body mass to grow ( anabolism ). So little is available for the plants. This determination of inorganic nitrogen to organic nitrogen compounds called nitrogen immobilization. It affects the nitrogen mineralization (nitrogen fixation, ' nitrogen utilization ' ) counter.

The nitrogen immobilization and thus the nitrogen deficiency of the crop is temporarily: Is the degradation process come once in motion, is slowly degraded nitrogen and the nitrogen balance evens out again. If at the end of the microorganisms die, they are themselves the source of nitrogen. The fixed nitrogen is released with the decomposition of organic substances in the long term again.

This enables them to suffer as a result, no nutrient deficiency, the nitrogen must be supplied from outside. Have proved successful in perennials amounts of 50 to 80 g per square meter horn shavings. Only after distributing this slow and sustained-release organic fertilizer, the bark mulch is applied at a thickness of 5 to 8 cm. It is also convenient to compost difficult decomposable litter before. The more mature compost, the smaller the risk of Stickstoffimmobilisierung.

Is there, however, a nitrogen excess, the C / N ratio is too narrow and it can lead to the formation of ammonia, which is also the pH for the degradation moves unfavorably. If this is the case, for example, sawdust or straw can be mixed.

Disadvantages

• A Mulchbeet can be badly chopped remove without the mulch layer.
• Especially on heavy clay soils it obstructs the heating by the sun.
• An undesirable side effect of mulching is that worm infestation can be favored by the organic garden waste, particularly in dense, moist mulch such as fresh grass clippings.

Mulching is an important contribution to long- term soil fertility and tilth.

Mulching in agriculture

In agriculture or large-scale garden culture as well as the landscaping mulch also known for mowing with simultaneous crushing of the mulch material. These sickle or flail mulchers are used which are available in different design to the front, interaxle and rear - mounting for tractors or cultivators.

Advantage over the mowing is that even tough and woody plants can be abgeschlegelt and crushed it. The mulched remains - very finely sliced ​​- lie on the surface and rotted there much faster than long-stemmed crop. So mulching landscape management is a replacement where mowing or grazing are not possible, eg because the vegetation for forage is unusable, or the disposal of the crop would be too expensive. Mulching is therefore a part of the Barrens economy.

Prerequisite for the receipt of agricultural EU subsidies since 2005, that fallen from the use of arable and Gründlandflächen from subsidy recipients (farm ) mulching (also mowing with clearing every two years for grassland ) are kept open, before the encroachment protected be. This is to ensure that not be profitable available agricultural land not only remain Usable as is, but will also improve their soil quality.

In keeping it open attempts by the State of Baden- Württemberg, the effects of mulching of grassland areas are examined for different locations as a landscape maintenance operation since 1975 and compared with the development in undisturbed succession.