A pot experiment was performed in the net house to observe the influence of cow dung and poultry manure on the growth of red amaranth grown in the amended soil (mixture of acid and calcareous soil). Acid soil was mixed with calcareous soil at a ratio of 3:1 for experiment with red amaranth. The pot experiment was conducted with the mixed soil indicated by T0M (control-where no amendment was added), three different rates of cow dung such as T1 (3 ton/ha), T2 (6 ton/ha) and T3 (9 ton/ha) and three rate of poultry manure designated as T4 (2 ton/ha), T5 (4 ton/ha) and T6 (6 ton/ha). Treatment responses were evaluated in terms of different parameters including uptake of nutrients by plants and post-harvest properties of soil such as physico-chemical properties and residual nutrient content of the soil. It is evident from the experiment that the uptake of the plant nutrients was the best in the mixed soil (T0M-control) than those of the acid (TA) and calcareous soils (TC). On the other hand, T3 (9 ton cow dung/ha) showed the highest uptake of nutrients except for S and Mg among the all treatments. In the post-harvest soil, the maximum nutrient contents increased in the highest doses of cow dung (except for the S, Cu, Mn and Zn) and poultry manure (except for the K, Ca, Mg and Fe) treatments. Results of the study showed that soil amendment (mixture of acid and calcareous soil) can be a suitable reclamation process while the addition of organic manures can also improve soil health. Dhaka Univ. J. Biol. Sci. 31(2): 329-342, 2022 (July)

A field experiment was carried out to investigate the effects of vermicompost (0, 10, and 15 tha-1), climatic elements i.e. soil moisture (50%, 70%, and 100%) and elevation of soil temperature (1 to 20C) on the physico-chemical properties and nutrient availability of post-harvest calcareous-acid mixed soils after rice production. A total of 18 treatments assembling the afore-mentioned doses was applied. The analyses of the soils demonstrated significant variation in effects (p ≤0.05) of the treatments on both the available nutrient status and the physicochemical properties of soils. Except for available sulfur; soil pH, EC, organic carbon (OC), available nitrogen, phosphorous, potassium, calcium, and sodium were detected in the higher amounts in 1:1 (calcareous : acid-soils) mixed soils than those of 1:3 mixed counterpart both in initial and post-harvest soil conditions. The highest levels of soil pH, OC, available P and Zn were determined in the treatment T13. Whereas, treatment T6 proved to be the best dose for the highest availability of Ca and Mg. The treatments T1, T2, T11, and T16 were recorded to have the lower OC, available N, P, Ca, Mg, Zn and S contents in soils. In particular, the availability of Na was found to be in lesser amounts in all the subplots. In a nutshell, most of the treatments exerted favourable influence in maintaining a healthy level of soil physico-chemical parameters owing to their inherent characteristics. Dhaka Univ. J. Biol. Sci. 32(1): 119-134, 2023 (January)