It is essential to improve land quality to grow more and to meet the increasing demands for food and other essential agricultural items, large-scale use of chemical fertilizers is not advisable.
Chemical fertilizers can improve soil and land quality, but these are costly. Also, excessive use of chemical fertilizers causes eutrophication of water bodies as a result the run off. Other alternative will have to be looked for. The best alternative is to utilize natural resources for land improvement.
Methods to Improve Land Quality for agriculture
1. Organic Farming
Organic fertilizers in the form of biomass and waste products cannot only provide nutrients to soil but also enrich hums content.
Biomass is used as fuel in the form of dung cakes, dry leaves, agricultural residues and the like. If these are utilized to improve soil quality, the benefits may be much more.
Use of raw dung as fertilizer is not advisable, because if dung is raw, it attracts white ants, which ultimately eat away the roots of vegetation growing in the area. Composted dung does not attract white ants and consists of nutrients in readily available form. As another version of composting the cowdung, it can be first used for generating biogas like “Gobar-gass” and then the decomposed product can be used as fertilizer. So, not only will the energy demand be met in a cleaner way but also the fertilizer value will be properly used.
Another way of improving land quality is to grow those plants species, which add nutrients to soil. Generally, plants extract nutrients from soil. But there are certain specifies of plants mainly belonging to the leguminous group which fix nitrogen from atmosphere and add it to soil. These species can grow on very poor soil and in turn, they improve the soil.
So, if we have a land area which is poor in nitrogen, we may grow leguminous plants such as pea, lathyrus, dhaincha, chandani, etc. for a few seasons on the land. Care should be taken to allow maximum amount of biomass from these plants to mix with the soil. Within a short time, the soil may improve to such an extent that other crops can be grown successfully there.
2. Mixed Cropping
A modification of this technique can be made. Leguminous crops may be grown alternately with other crops on the land. This is called “crop rotation”. So, nutrients are absorbed by one crop while the other crop makes good the loss. Slowly, the land quality improves. Another modification is “mixed cropping”. Here on-leguminous and leguminous crops are grown together in the same area in a mixed pattern. So, one crop derives nutrients from the soil while the other adds.
3. Use of Halophytes
Unscientific irrigation may also lead to degradation in land quality. Excessive irrigation leads very often to sanitation or alkalinisation of soil. The irrigation water evaporates leaving the dissolved salts behind. In our country, very large areas are affected by salinity and alkalinity. Together, these are called salt-affected soils.
Once, the soils become salt-affected, they are rendered almost useless for agriculture, as crops do not grow there successfully. These areas are generally left fallow. But these soils can be reclaimed mainly by growing special types of plants’ (halophytes) which are tolerant to salinity or alkalinity. When these plants grow there, the soil condition becomes better and finally other species can also be grown. They provide cover on otherwise infertile soils because, they survive better, improve the soil faster and also provide hay for the livestock.
4. Aerial Seeding
For large-scale improvement of degraded land, the Government has created a separate programme called “National Mission on Wastelands Devolvement” under the Ministry of Environment and forests. This mission provides funds for training people, rasing seedlings, carrying out plantation and afforestation to bring degraded land into use and grow fuelwood, fodder, forage, etc. if they cannot be used for grain production.
As a result, the pressure on natural forests, grasslands, and grazing grounds may be reduced. It also checks soil erosion and further degradation of land. For difficult sites, aerial seeding practices are also adopted. Packets containing seeds along with a little fertilizer are sprayed just before rains form aircrafts and they are left to grow undistributed. Slowly, the degraded land is transformed into productive area. A good example is afforded by hills near Islamabad, Pakistan.
5. Land Use Planning
It is essential to plan beforehand how land is to be used. For example, cities, highways, roads and dams should be built on degraded land areas. These requirements should be met with minimum possible disturbance to agriculture and forestry.
Cities should not be permitted to grow beyond an optimum limit. Industries may be established utilizing land, which is otherwise useless. Agricultural production should be increase by adopting better crop management measures and technological innovations and not by bringing more areas under agriculture through forest clearance. Fallow land in the proximity of cities and towns may be costlier than these. So, the tendency is that people go for those lands for uses other than agriculture. This must be stopped.
Land use should also take into account land capability: the quality of land and the economic use to which it can be put. For example, if we use a poor quality land for agriculture purpose, the cost involved will be high and production will be low. But the same land may be suitable for growing some tree or grasses or shrub species which may be used as fuel, fodder or fiber. This type of practice should be adopted. This would generate more benefits and also reduce pressure on other land areas.
Even in the case of agriculture, proper planning is essential. Mixed cropping or rotation cropping practices should be adopted. Irrigation must be scientifically planned. Excessive irrigation should be avoided and proper avenues for drainage be kept, otherwise that land may become salt affected. Those land areas where nothing can grow may be earmarked for buildings, roads, factories, etc.