SUMMARYNo-tillage and raised beds are widely used for different crops in developed countries. A field experiment was conducted on an irrigated maize-wheat system to study the effect of field layout, tillage and straw mulch on crop performance, water use efficiency and economics for five years (2003–2008) in northwest India. Straw mulch reduced the maximum soil temperature at seed depth by about 3 °C compared to the no mulch. During the wheat emergence, raised beds recorded 1.3 °C higher soil temperature compared to the flat treatments. Both maize and wheat yields were similar under different treatments during all the years. Maize and wheat planted on raised beds recorded about 7.8% and 22.7% higher water use efficiency than under flat layout, respectively. Straw mulch showed no effect on water use and water use efficiency in maize. The net returns from the maize-wheat system were more in no tillage and permanent raised beds than with conventional tillage. Bulk density and cumulative infiltration were more in no tillage compared with conventional tillage.

Continuous rice-wheat (RW) cropping with intensive tillage has resulted in land degradation and inefficient use of water in Indo-Gangetic Plains (IGP) of South Asia. Replacement of rice with less water requiring crops such as soybean in RW system and identification of effective strategies for tillage management could result in sustainable cropping system in IGP. A field experiment was conducted for five years on an annual soybean-wheat (SW) rotation in the northwest IGP of India to evaluate effect of tillage, raised bed planting and straw mulch on yield, soil properties, water use efficiency (WUE) and profitability. In soybean, straw mulch reduced soil temperature at seeding depth by about 2.5 • C compared with no mulch. Straw mulch also resulted in slightly reduced water use and slightly higher WUE relative to their respective unmulched treatments. During wheat emergence, raised beds resulted in higher soil temperature by 1.6 • C compared with flat treatments. Bulk density and cumulative infiltration were greater in no-tillage compared with conventional tillage. Soil organic carbon in surface layer increased significantly after five years of experimentation. Soybean and wheat yields were similar under different treatments during all the years of experimentation. Soybean and wheat planted on raised beds recorded about 17% and 23% higher WUE, respectively, than in flat layout. The net returns from SW system were greater in no-tillage and permanent raised beds than with conventional tillage. Both no-tillage and permanent raised bed technologies can be adopted for sustainable crop production in SW rotation in northwest IGP. However, more studies are required representing different soil types and climate conditions for making recommendations for other regions of IGP.

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The goal of this work is to investigate the application of integral minus proportional derivative (IPD) controller for the automatic generation control (AGC) problem comprising of a two-area thermal system integrated with renewable energy (RE)based sources such as wind, solar and fuel cells. In order to facilitate a realistic environment, each thermal system is equipped with a governor dead band, reheat turbine and generation rate constraint. Moreover, each RE-based power system is modelled by incorporating certain drift and random variations as the key characteristic of RE-based sources. The control performance of IPD is compared with the PID and PI controllers all tuned using an evolutionary technique genetic algorithm by incorporating a step load perturbation in both areas. In order to verify the effectiveness of the control scheme, detailed performance investigations are carried out using random variations in load perturbations and in RE-based power. In addition, sensitivity analysis is also included for wider variations in system parameters in order to test robustness. Based on the extensive simulations for robustness and accuracy, it was observed that IPD outperforms the other controllers and therefore serves as a promising solution to the problem of AGC.