Author: Ing. Ag. (Mg. Sc.) Marcelo De León. Inta Manfredi
The grasslands are “plant communities” in which different species interact with each other and with the environment in which they occur. This interaction refers to skills for space, light, water and nutrients between plants that make a pasture, whether of the same species or not.
are presented and different types of grassland depending on the type of component species, from those dominated by grasses (mountain pasture) to those in coexisting woody species (trees and shrubs) with grasses and herbs, such as forests and mountains of the north and west of the province.
In general, the whole area covered by natural grasslands the country, there are different degrees of degradation with respect to the equilibrium situation in which they were before colonization. With the advent of logging of man and domestic livestock, it breaks the original balance and begins the process of degradation. But what does this degradation?.
From the standpoint of natural grassland forage resource, in the first instance means a loss of productivity, driven primarily by variations in the components of the original community. In this process, there was a gradual decrease of the more palatable and better forage, which were replaced by smaller species or no value or invasive species. In some cases it has been the total disappearance or extinction of valuable forage, which is not only a less production, but the loss of genetic material impossible to recover or “genetic erosion”.
This process is the result of a habit of grazing selective cattle which to form your diet, seek and consume primarily those species most prized and highest quality. In these grasslands have been managed with high stocking rates (above the one you are capable of supporting) and without any break or management, continuous grazing on these species, made to decrease its ability to compete with the less preferred. The high frequency and intensity of defoliation to which they were subjected, in the death of the best forage and the proliferation of undesirable species. This process can continue until the loss of ground cover, erosion and productivity zero.
However, it must be attributed the blame for this degradation of grassland animals that graze, but the man who makes decisions about its use. But if the decisions are correct, it may tend to reverse this process towards a recovery of natural grasslands by management standards based on knowledge of their operation.
Knowing the grassland; Status and Key Species
First, we must recognize the “condition” that each pasture is grassland. This refers to the state or degree of degradation found for which it should consider a range of indicators including:
- The proportion of different types of species, classified according to their characteristics fodder (animal preference, productivity and quality) as:
- The force of the best species (size of the plants, as outbreaks, etc..)
- The amount of annual plants or weeds
- The proportion of bare soil (no cover).
The relationship between these indicators and range condition and forage production can be seen in Table 1.
Table No. 1
|Condition||Predominant species||Vigor best species||No. of annual weeds||Bare soil||Forage production|
Forage production (expressed as kg DM / ha) is the basis for determining the stocking rate that is capable of supporting each paddock of natural pasture.
Secondly, it is necessary to recognize and define some “keystone species”, based on which l will centralize management of pasture and let go following the evolution of the condition. They are considered keystone species, preferably those with good animal, d high forage production capacity, good quality and are perennial. They that seek to proliferate with proper management, are there to look after.
Elements of Management
The objective of proper management, is planning the use of rangelands, designed to achieve maximum animal production, financially supported, compatible with the conservation and / or improve them.
are several elements that are in place to meet with this objective, based on the decision to recover the forage resource.
1. Adequacy of stocking
It refers to the number of animals must conform to each pasture forage production, while ensuring a level of use. This means you must leave a surplus for the survival of key species of importance to soil cover. This level of use is the proportion of dry matter forage can be grazed accumulated without affecting the plant and found to vary between 50 and 60%.
the receptiveness animal, closely related to range condition .
This relationship, for pasture north of Cordoba, can be quantified as follows by way of example Table 2. This is important because to be improving range condition, the load can be increased and thus the production of meat / ha (going from fair to good means duplicate).
C OX N ° 2
|Condition||Responsiveness animal (ha / livestock unit)|
Making a break from a paddock of natural pasture means complete withdrawal from the same animals for a period of time. These are of great importance especially for recovery and may have any of the following objectives:
â€¢ * Allow seeding and dissemination of grazed more species, which is achieved by implementing your plant number for natural reseeding
This should be done in is the time ripe summer-autumn for spring and summer species to species of winter.
* Allow the germination and development of new plants from seed production before. Appropriate times are, for species spring summer and fall to winter.
* Increase the force of the existing key species, resting on pasture during the active growth of the same.
The organization breaks and periods of use of different pastures, give rise to “grazing systems” that can be implemented as another element of management. The supplementation of natural pastures pastures cultivated or other item of great importance for management. These issues will be addressed in the second half.