the first step in policy making is describing the objectives and choosing the policy instruments and management strategies and then, analyzing and assessing the impacts of them. in this study, farmers’ responses to selected policy instruments and management strategies were assessed using a semi-distributed planning model in qazvin irrigation and drainage network. the proposed model, simulates t...

Water availability is the key factor determining maize yields in NE Spain. Irrigation is needed to obtain economic yields but it is costly and water supply is sometimes insufficient. The aim of this research was to test a simple simulation model for evaluating different irrigation strategies, especially under water-limited conditions. The LINTUL model was adapted and parameterized using experim...

Partial root-zone drying or partial root-zone irrigation is a newly proposed water saving technique which may improve water use efficiency and nutrient uptake by a crop without affecting its yield. A study was conducted to investigate the response of furrow-irrigated okra to partial root zone drying in relation to cropevapotranspiration (ETc), vegetative growth, yield, and nutrient use effi...

The water use efficiency under conventional flood method of irrigation, which is predominantly practised in Indian agriculture, is very low due to substantial conveyance and distribution losses. Recognizing the fast decline of irrigation water potential and increasing demand for water from different sectors, a number of demand management strategies and programmes have been introduced to save wa...

Irrigation water demand accounts for more than 95% of the total water use in the Kaidu-kongqi River Basin. Determination of the spatial and temporal trends in irrigation water demand is important for making sustainable and wise water management strategies in this highly water deficit region. In this study, the spatial and temporal trends in irrigation water demand as well as net crop irrigation...

Irrigation scheduling is an important decision problem in agriculture. The purpose of the study presented in this paper is to compare dynamic programming (DP) and reinforcement learning (RL) methods for identifying optimal starting irrigation strategies, when a limited amount of water is available for irrigation. Both of the optimization methods use the MODERATO simulator, which includes a grow...

When people learn that I study lethal injection, they are usually curious to know more (or at least they are polite enough to ask questions). Interestingly, the question that arises most often— from lawyers, law students, and laypeople—is why states behave as they do. In the wake of botched executions and ample evidence of lethal injection‘s dangers, why do states fail to address their executio...

A student, supported by his classmates, throws a piece of chalk at the teacher who is writing on the blackboard. The teacher rapidly turns back and promptly catches him in the act. The student blushes and suddenly realizes how bad it was what he did. What happened to the guy? Why did he decide to throw the piece of chalk? And why, after a few seconds, he would have liked that what he did had ne...

Nitrogen (N) uptake (kg ha-1) of field-grown potatoes was measured in 4.32 m2 lysimeters that were filled with coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI after tuber bulking and lasted for six weeks until final harvest. Results show...