Tree Planting in Problem Soils - Hard Clayey Soils

Hard Clayey Soils


These are the soils in which clay particles constitute over 35% or more of the total weight.  These soils are extensively distributed in salt range foot hills of Punjab and western Kohistan of Sindh.  The plants that grow in these soils have to face the following problems.


  • Soil is compact. There is lack of aeration and drainage. Root penetration and respiration is restricted. Soil is usually shallow due to presence of Ca pan in the lower horizons. This leads to reduced water storage in the thin surface layer of the soil which is exhausted very soon.
  • Because of high adsorptive power of clay, even a slight but continuous addition of Na is enough to cause deflocculation which is very harmful phenomenon for plants.


Some kind of help will have to be provided during establishment of vegetation and initial growth stages. Once establishment and having gained complete control of site, the vegetation will by itself bring rapid improvements in soil conditions and will significantly ameliorate the microclimate. The presence of plant canopy and litter will prevent evaporation from soil surface and will, therefore minimize the development of crevices and fissures. The addition of humus and the activity of subterranean fauna such as insects, worms and rodents etc. will improve the soil structure that will result into easier root penetration, better aeration and better drainage. Such a soil will eventually become highly productive as a result of permanent woody vegetation.
The following points should be kept in view while undertaking any planting in such area:



  • Suitable species should be selected. Such a species for example should be hardy, drought resistant, fast growing and should have a high turnover rate. Species having deep root system should be preferred. A few examples are; prosopis, Syzygium, Albizzia etc.
  • Large sized plants with intact root system be used. Potted plants or the one with balls of earth be preferred. Necessary pruning of branches should be done just prior to or after planting in order to improve root shoot ratio in favour of roots.
  • A large pit of 1 meter diameter and 1.25 meter depth be dug. One should make sure that kankar (hard Calcium) pan, if present, is broken. This will increase the depth of available soil. An 8 cm thick layer of pure sand or fine gravel be provided at the surface of each pit. This will cut down evaporation loss of soil water. More water thus becomes available to plants.
  • The pit should be filled with a mixture of soil, coarse sand or gravel and organic manure. Sand is, however, most important component. This will improve aeration and drainage and will minimize crevices and fissures and breaking of roots.





Popular posts from this blog

Grafting Method - Inarching or Approach Grafting

Image
Inarching or Approach Grafting Unlike other grafting operations, in inarching the scion is attached to the stock while it is still attached to the parent plant. Round the world, the method has been extensively used in the vegetative propagation of mango. The method involves potting healthy one-year- old seedling in earthen pots, which are usually 12 in deep and 8 in wide at the top. The earth ball along with root system is kept intact and placed in the pot. The unfilled space in the pot is then filled with a mixture of well- rotted manure and canal silt. The soil is firmly pressed around the earth ball and the transplanted seedlings are then watered. Potting of seedlings is usually done one month ahead of actual inarching operations. This allows sufficient time for the seedlings to set before grafting. Inarching can either be done in the spring months or in the rainy season. July and August are preferred over the spring season because after inarching operations in the spr
Read more

Parent Material of Soil

Image
Parent Material of Soil Unconsolidated product of weathering from which soil develops is called parent material. Generally there are two groups of parent materials, i.e. sedentary and transported. The transported materials are further subdivided according to transporting agency and place of deposition. Sedentary or Residual                                            The parent material formed in place and still at the original site. Transported                       The parent material carried and deposited by various transporting agencies. By gravity- Colluvial By water- Alluvial By ice- Glacial By wind- Eolian The nature and properties of parent material together with climate are the most important factors affecting the kind and quality of soils. So to understand soils we must know the source of material, mechanisms of weathering and transporting agencies. Sedentary or Residual Parent Material                                                      
Read more

Green Manuring

Image
Green Manuring A growing crop that is plowed under and mixed with soil to enrich the organic matter is called green manure crop. The practice of plowing under or soil incorporation of such green manure is called green manuring. Green manures are mostly leguminous crops which are high in nitrogen contents. Generally following crops are suitable for green manuring: Jantar, Guara, Cow peas, Alfalfa, Sun hemp and Clover etc. Criteria for the selection of green manure crops It should be fast growing and easily established. It should produce abundant and succulent biomass. It should be well adapted to the local conditions. Growth habit of crop should encourage ground cover soon after its establishment. It should be able to fix nitrogen in the soil. It should have a wide climatic and soil adaptation and ability to grow on poor soil. Advantages Improves the soil fertility Adds nutrients and organic matter to the soil Improves the soil structure Improves soil aer
Read more