Pasture Development: Needs and Problems

Pasture Development: Needs and Problems

KHILENDRA BASNYAT

The development of pastures is of immense importance for livestock and therefore for human beings. Pastoral agriculture is developed in tropical parts of Australia, Africa and the Americas. Pastoralists made all out efforts to practice on different plants and environments as far as they were able, and their activities were mostly confined to regions where grassland or grassy woodlands occurred naturally. In fact, it has only been within the last fifty years that man began to study these tropical grasslands.

Scientific effort towards the development of improved grass-legume pastures has been almost entirely within the last thirty years. Australian researchers have been fortunate enough to be given the resources to contribute to this field. Consequently, there has been a marked increase in the areas sown to improved tropical pastures in Northern Australia. This has resulted in a new industry in the production of seed of tropical legumes and grasses.

In the tropics, the flatter regions of fertile soils are limited in area and are usually preferred for cultivation. It is only the very extensive tracts of infertile and usually the hilly region unsuitable for cropping that at present provide grazing for most livestock and ruminants in the tropics. The areas receiving adequate rainfall offer the greatest challenge for pasture research to develop improved pasture systems capable of greatly augmenting agricultural production. In the vast arid and semi-arid areas lying in the tropics, where there is insufficient rainfall, the establishment of improved pastures has become more complicated day by day.

Nowadays semiarid grazing lands are being destroyed at a faster rate than the capacity to regenerate. The conversion of productive areas into deserts is seen around the edges of the Sahara, the deserts of the Middle- East, Pakistan, Mongolia, Australia and Western North America.

In densely populated countries like India and Thailand and areas like Java, most farms are small (about 5 to 10 ha) and intensively cropped, and livestock are reared mainly for drought purposes. In these areas, land is considered scarce commodity.

Overgrazing has led to the massive destruction of pastures in some places which has caused grave economic loss to nomadic populations. It has also turned non-desert areas into deserts, a process termed desertification which is increasing at an asymptotic rate.

In the past, grazing animals were kept in check by natural factors such as rainfall and consequently by the availability of water. However in modern times, there has been little effort to manage the grasslands and to let them periodically rest and recover. Rotational grazing together with overstocking has led to decreasing productivity, erosion, a drying up of springs, wells and rivers, and the growth of man-made deserts.

In many countries, in recent times, desert like tracts have appeared because of human misuse of vegetation and soil through overgrazing. In many parts of East Africa, West Africa and Madagascar, the area of deserts is spreading at an alarming rate. Due to overgrazing, vegetation and wildlife rapidly disappear by erosion and give way to deserts.

Treading certainly affects both the growth and the botanical composition of pastures. Serious damage is more likely to occur when the soil is wet. The degree of damage varies with the structure of the space, in particular whether it has met or not. It also varies with the nature of the soil.

The extent to which treading is dispersed or concentrated will be important and will vary with the tendency of species to flock on herd to make and follow well established tracks and the speed and weight of the animals involved. Both kinds of damage to plant and soil are greatly increased when the animal has hooves and when it is accelerating. Hooves not only possess sharp cutting edges, but they carry the weight of animal on a very small surface. This causes high downward pressure when the animals walk and horizontal forces when they run or accelerate.

Keeping in mind the present state of the world’s pastures and their important place in the ecosystem, it is imperative to comprehend the important role pastures play in stabilizing the water cycle and preserving the soil. It is also equally important to understand that pastures cannot exist without either of these renewable resources. Pastures not only facilitate evaporation but also keep the soil porous. Important salt nutrients both from the air and the rains, essential for vegetable and animal life, also flow to the soil and subsoil water. If the pastures are destroyed, there is a great possibility that the fertile soil layer will disappear. When the vegetation dies, so do the animals.