Effects of Mulching on Soil Water Content, Maize Performance and Weed Growth in Dry Land Area of Bangladesh

Aims: The objectives of the research work were to evaluate the effects of mulching on soil water content, maize performance and weed growth in dry land area of Bangladesh Study Design: The experiment was laid out in a randomized complete block design (RCBD) with three replications Place and Duration of Study: Central research field of Sher-e-Bangla Agricultural University, Dhaka-1207 during November 2019 to April 2020. Methodology: The experimental field is divided into 3 blocks to represent 3 replications. There are 6 unit plots (each unit plot consists of 3m � 2m area) in the experimental farm. Distances of 1 m and 0.5 m are maintained between replication to replication and plots to plots, respectively. Plant to plant and row to row distances are considered to be 0.25 m and 0.75 m, respectively. The treatments are assigned in random plots. The land is ploughed four times followed by laddering to have fine tilth of the soil. The maize cultivars Shuvra and KS-510 are used as plant materials. Fig. 1 represents the six mulch treatments are imposed on the plants: Control (without mulch, CK), water hyacinth dry (10 t/ha, WH), rice straw dry (10 t/ha, RS), black polythene (4m � 3m, BP), white polythene (4m � 3m, WP), and transparent polythene (4m � 3m, TP) (S2). The mulches are applied as per treatment in each plot just after sowing to maintaining an equal thickness throughout the plot. Dried and cleaned mulches are used before applying to the experiment. The significance of the difference among the treatment means were estimated by the MSTAT-C package programme at 5% level of probability. Results: It is found in the experimental results that the soil water content of the no-mulching treatment is lower as compared to that of the other treatments from 0-10 cm, 10-20 cm and 20-30 cm soil depths. It is also observed that the RS mulching provides the highest soil water content, leaf area index (LAI), chlorophyll contents, and total biomass. Significant enhancement of maize yield (20.55 ton/ha) is recorded for the rice straw mulching. In contrast, the weed dry weight of 7.45g/m2 is observed in the RS mulching, which is lower than the other treatments. Conclusions: Therefore, it can be concluded that the RS mulching, compared to other mulching, would be more efficient for maximum utilization of limited water resources, weed suppression as well as to increase the maize yield. The present research approach would be applicable to manage the soil water for enhancing the maize production in dry land area.

Effect of losartan and enalapril on cognitive deficit caused by Goldblatt induced hypertension.

The present study was designed to evaluate the learning and memory, in an altered physiological state associated with increased blood pressure and activated renin angiotensin system in Wistar rats. The role of angiotensin in cognitive function was assessed by treatment with angiotensin converting enzyme (ACE) inhibitor enalapril (2 mg/kg), angiotensin 1 receptor (AT(1)) antagonist losartan (5 mg/kg) and their combination. The experimental renal hypertension was induced by the method of Goldblatt. Learning and memory was assessed using the radial arm maze test. Acetylcholine esterase (AChE) levels in the pons medulla, hippocampus, striatum and frontal cortex were measured as a cholinergic marker of learning and memory. Results indicate that in comparison to normotensive rats, renal hypertensive rats committed significantly higher number of errors and took more trials and days to learn the radial arm maze learning and exhibited memory deficit in the radial arm maze retrieval after two weeks of retention interval, indicating impaired acquisition and memory. Treatment with enalapril, losartan and their combination attenuated the observed memory deficits indicating a possible role of renin angiotensin system in cognitive function. AChE level was reduced in hippocampus and frontal cortex of renal hypertensive rats which could be attributed to the observed memory deficit in hypertensive rats. It can be concluded that, renal hypertensive rats had a poor acquisition, retrieval of the learned behavior, perhaps a possible disturbance in memory consolidation process and that this state was reversed with ACE inhibitor enalapril and AT 1 receptor antagonist losartan.