Soil Science - Study Mode
[#216] Useful practice to manage acid sulphate soil is
Correct Answer
(B) Keeping the soil waterlog
Explanation
Solution: Acis sulphate soil is the soil or sediments containing iron sulphides. Iron sulphides are micro-crystalline minerals such as pyrite that have formed naturally in soils where long-term water-logged conditions occur. When it is disturbed by drainage, lowering of water tables, or excavation, oxidation of the sulphides creates sulphuric acid which can trigger a range of flow-on effects. Thus, the useful practice to manage acid sulphate soil is keeping the soil waterlogged.
[#217] Plant analysis is useful if done at
Correct Answer
(C) early stage
Explanation
Solution: Plant analysis is a crop management tool that has been stimulated by the increased use of scouting programs and crop consultants. The information provided through plant analysis helps farmers with decisions on the effectiveness of fertilizer, the need for additional nutrients, and planning fertilizer programs for future use. It is required plant analysis is useful if done at an early stage.
[#218] Humus forming fungi includes which genera
Correct Answer
(D) Both B and C
Explanation
Solution: Humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter by the act of micro-organisms i.e. bacteria and fungi. It is rich in nutrients and retains moisture in the soil. Organic matter is humified by a combination of saprotrophic fungi, like Alternaria and Aspergillus. Whereas Trichoderma strains are used for biological control of plant disease.
[#219] In Oxisol which type of Clay is found
Correct Answer
(A) Kaolinite
Explanation
Solution: Oxisols are a soil order in soil taxonomy, for their occurrence in the tropical rainforest. The main processes of soil formation of oxisols are weathering, humification and pedoturbation due to animals. Oxisols are specified by a thick subsurface layer that contains kaolin-group clay minerals ie. Kaolinite and metal oxides in a finely textured matrix with very little or no easily weathered silicates.
[#220] If quartz & feldspar are predominantly observed in sandstone, then it is called
Correct Answer
(C) Arkose
Explanation
Solution: Arkose is a coarse sandstone primarily made up of quartz and feldspar grains together with small amounts of mica, all moderately well sorted, slightly worn, and loosely cemented with calcite or less commonly, iron oxides. Closely resemble granite in appearance and is frequently utilized as a building material.