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ANN and RSM based modelling for optimization of cell dry mass of Bacillus sp. strain B67 and its antifungal activity against Botrytis cinerea

In this research we explore the potential of precision surface irrigation to improve irrigation performance under the warabandi system prevalent in the Indus Basin Irrigation System. Data on field dimensions, field slopes along with characteristic soil infiltration properties and outlet discharge were collected through a survey of a sample tertiary unit of Maira Branch Canal, Khyber Pakhtunkhwa Province, Pakistan. The performance of all fields in the tertiary unit was analysed and reported in aggregate, with detailed results of one field presented for illustration. The objective is to determine the optimum field layout, defined as the number of border strips, for the observed field characteristics to maximize performance. The results indicate that performance improvement is relatively easily achievable through changes in field layout within current irrigation services. Estimated application efficiency is sensitive to the selected depth of application, and it is important that a practical depth of application is selected. We recommend a depth of application of 50 mm and show how this is achievable and leads to a low quarter distribution uniformity of 0.750 and an application efficiency of 80 %. We also explore the feasibility of a 10-day warabandi rather than the 7-day warabandi and show that there is no significant change in the performance under a 10-day warabandi

Excessive irrigation and poor drainage conditions are the major factors contributing to rising groundwater tables and soil salinity in the irrigated areas of Central Iraq. Therefore calculations of precise irrigation requirements are necessary to optimize crop production and keep the groundwater table below the root zone to avoid soil salinization. In this study, the soil–water–atmosphere–plant (SWAP) model is used to determine optimal groundwater table depth and irrigation amounts for the study area. SWAP was calibrated using field data from the study area during the wheat and maize season of 2011–2012. The modelling results reveal that under current irrigation practices (600 mm to wheat and 1000 mm to maize), more than 30% water is lost as deep percolation. This causes a rise in the groundwater table and reduction in crop yields. The model simulations suggest that a groundwater table depth of 200 cm together with an irrigation application of 500 mm to wheat and 600 mm to maize will be the best combination to attain optimal yields. Therefore a drainage system in these areas should be installed to maintain groundwater table depth around 200 cm. Maintaining adeeper groundwater table will not be suitable as costs will increase and crop responses negligible. For long‐term sustainability, rehabilitation of existing drainage systems to evacuate excessive salts from the root zone will be imperative. Copyright © 2013 John Wiley & Sons, Ltd.

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