Modification of chemical composition of pasture plants by soils
1937
Midgley, A.R.
Plants are materially affected by the nature of the soil on which they grow. If the soils are high in available plant nutrients, it will be reflected in the chemical composition of the plants and likewise in the performance and physical condition of the grazing animals. There are many soil and pasture areas that are known to produce nutritional disorders. Lack of certain minerals, such as calcium and phosphorus, in the herbage are perhaps most common, but insufficiency of iron and copper found on some soil types leads to animal anemia. Goiter is prevalent in areas where iodine content of soils and plants is low. An excess of fluorine may produce teeth disorders. Some soils produce vegetation carrying lethal doses of selenium. Soil texture has a pronounced effect on the availability of moisture and plant nutrients. Fine-textured soils are better able to store up and hold these materials than the more sandy types, and they usually produce better vegetation higher in minerals and digestible nutrients. Clay loams or fine-textured subsoils containing much colloidal material are better able to withstand drouth than the more open sandy soils or subsoils. Since available moisture is often a limiting factor in the production of good pasture, it is evident that soil type has a marked effect on the quality and quantity of herbage. Soil type greatly affects the kind of plant it will support. If sufficient moisture and minerals are present, more clover will be produced than where these essentials are lacking. Since legumes contain more protein and minerals than the grasses, it is evident that soils by influencing the botanical composition indirectly affect the chemical composition of the herbage.
显示更多 [+] 显示较少 [-]