Hello Kinfe

• Organic matter , such as well-prepared, mature composts or animal manure particularly, contain many of the nutrients required by plants which are held by weak chemical bonds (ion binding sites). So the compost acts as a reservoir from which the plant's roots can extract the nutrients as required. This `smooths' the supply and provides nutrients when demand is large - during certain growth stages. Also, the organic matter is broken-down and metabolised by soil organisms thus freeing nutrients which can be removed by plants. Further, organic matter increases the water-holding capacity of soils, which is generally an advantage. Sandy soils (predominantly silica) are lacking in ion exchange sites and in water holding capacity compared to clays, which have complex ion exchange properties on the very small clay platelets and also much better water-holding characteristics. So sandy soils benefit from addition of manures. Soils in many parts of Africa have very little organic matter and so are of poor crop productivity. Hope this helps,

Organic fertilizers are mostly more effective in light texture soils because they can very easily be absorbed in it & trans located easily to different plant parts.

Hello Kinfe

• Organic matter , such as well-prepared, mature composts or animal manure particularly, contain many of the nutrients required by plants which are held by weak chemical bonds (ion binding sites). So the compost acts as a reservoir from which the plant's roots can extract the nutrients as required. This `smooths' the supply and provides nutrients when demand is large - during certain growth stages. Also, the organic matter is broken-down and metabolised by soil organisms thus freeing nutrients which can be removed by plants. Further, organic matter increases the water-holding capacity of soils, which is generally an advantage. Sandy soils (predominantly silica) are lacking in ion exchange sites and in water holding capacity compared to clays, which have complex ion exchange properties on the very small clay platelets and also much better water-holding characteristics. So sandy soils benefit from addition of manures. Soils in many parts of Africa have very little organic matter and so are of poor crop productivity. Hope this helps,

Hello,

Kinfe Tekulu

Soil texture indirectly influences the rate of organic matter(SOM) decomposition. Clayey or fine-textured soil tends to bind a larger amount of humus. There have been found many more binding sites of minerals and humus whereas Sandy or Coarsely Textured Soils are basically low in organic matter content and native fertility. Clayey soil, fine-textured soils that are not erosion-prone may lead to SOM stratification without increasing SOM sequestration. so, organic matter is readily bioavailable in coarse texture than its fixation in soil sites.

As compared with mineral fertilisers, Organic fertilisers contain organic matter besides nutrients. Applied on sandy soils, they improve the aggregation of soil particles and thereby improve soil texture. Biological activity and humus formation are stimulated.

Your results can be explained by the fact that sandy soil has very low water holding capacity, cation exchange capacity (CEC), organic matter, and nutrient contents. Adding organic fertilizer such as vermicompost improves all these soil characteristics which in turn leads to considerable improvement in crop yield. On the other hand, clayey soil has already high water holding capacity, CEC, and maybe also organic matter content (depending on the land use). Thus, the addition of organic fertilizer does not anymore lead to a considerable improvement in these soil properties mentioned above. Hence, it results in a less dramatic increase in crop yield.

light texture soils have naturaly low organic matter than heavey texture soils. for this reason adding organic mater to light texture soils gives beter respons than h heavey texture soils.

The organic fertilizers have ability to hold nutrients and prevent them from leaching. As we know light textured soils have low nutrient holding capacity compared to clayey soils. So results are more visible in light textured soils than heavy textured soils after application of organic inputs in said soils (light textured).

Heavy textural soils such as clay are compact and this compact structure of soils nature may not allow suitable environment for microorganisms like in organic soils. Organic fertilizers have sufficient microorganisms and they need enough space, moisture, aeration for efficient nutrient solubility and utilization of the nutrients from the soil by the plants. Whereas, compact soil structures such as in clay cannot help the nutrients easily and efficiently mobilized and utilized by plants' roots. So, application of organic fertilizers is proved more effective in light textured soils such as sandy and loam than heavy textured soils such as clay. Generally, clay soil and sandy soil means a matter of soil physical and chemical properties which has significant role on nutrient availability and utilization. The following link has very relevant information on the agenda: https://extension2.missouri.edu/mg4

(Soils, Plant Nutrition and Nutrient Management)

Thank you!!

The organic content of light soils (sandy soils) are usally low in humus content (organic matter), thus addition of this type of fertilizer provide variouse benifisery affects.

I agree with @Asio's answer!

It is quite interesting, that by using organic fertilizers, the agricultural products have been prepared. At present , it has become the commodity of rich people, but not a common man. The prices are exorbidant. In this cheating is also going on. No one has thought, after organic growing, how is the sensory attributes of the cooked product. In one of my studies, during my research at CFTRI, Mysore, I found the organic product miserably fails w.r.t sensory attributes. However, because of the demand for more agricultural products, always, there is a limitation to use organically grown agricultural commodities. Even recently some of the Ph.D thesis are coming out w.r.t organically grown agricultural products, which may be published in near future, may be in an year or so.

There is high leaching of nutrients are happen in sand dominated textural soils because of large pore spaces between soil particles, so addition of organic fertilizers to the soil improve the structure, water holding and adsorption capacity of the soil this helps us the nutrients from leaching down or degraded the soil.