جستجوی مقالات مرتبط با کلیدواژه « آنالیز حاشیه ای » در نشریات گروه « آب و خاک »

Water scarcity is a widespread problem in arid and semi arid regions. In this condition, evaluating crop response to water stress and estimation of ET production function (ETPF) is essential. The objective of this study was to investigate the dynamic interrelations of yield, evapotranspiration and water use efficiency of potato (Solanum Tuberosom L.) under trickle irrigation condition. This study was conducted in Dehgolan region of Kurdistan province in spring season of 1388. The experiment was arranged based on completely randomized block with 3 replication of water supply (60%, 80%, 100%, 120% of crop water requierment). In this study, evapotranspiration values and total yield of treatments were measured. To reveal the interrelations of yield, evapotranspiration and water use efficiency, two types of water production function including: Linear and Quadratic were used. The results showed that when the ETPF is linear, the EI will be numerically equal to the yield response factor (Ky), when ET reaches maximum ET (ETm). When ETPF was quadratic, the ET needed to maximize WUE is less than the ET for maximum yield (Ym). The results were also revealed that maximum yield was achieved at 345 mm of evapotranspiration and maximum water use efficiency (26.6 kg/m3) was achieved at 222 mm of evapotranspiration where 55.4 percent was less than the maximum evapotranspiration (ETm). However, the maximum yield was only 27.7 percent more than the yield in maximum water use efficiency. The interrelation of Y, ET and WUE are demonstrated that if water supply is limiting, seeking maximum water use efficiency may be desirable.

Due to limited water resources and occurrence of recent droughts, the use of new management and planning methods for optimal irrigation scheduling of agricultural crops is inevitable. Present of appropriate mathematical and dynamic relationship between yield, evapotranspiration and water use efficiency parameters is the first and most important step in the optimal management of irrigation and application of deficit irrigation strategy in the field level. Accordingly, In order to determine the water Production function of Basil plant, a pot experiment was conducted in completely randomized block design with four irrigation treatments include: 100, 80, 60 and 40 percent of water requirements and three replications in the glass greenhouse of Kurdistan University. The results showed, in linear water production function, marginal water use efficiency for evapotranspiration values is fixed. So, It is not suitable for explanation details of relations. however in the quadratic water production function of marginal water use efficiency decreased while the increasing of evapotranspiration. And in The evapotranspiration of 348 mm was cut water use efficiency curv. At in this point elasticity of water production is 1, and it has maximum water use efficiency. The results showed the Maximum yield occurs at 376 mm evapotranspiration. At in this point elasticity of water production is 0. Observed maximum water use efficiency and maximum yield don’t happen at a same point ET would need 8 percent greater than the ET for maximum water use efficiency, while the value of yeild increased by 4/2 percent. In addition to that, Yeild Response factor in the quadratic water production function is greater than this factor in the linear production function