‎in this paper‎, ‎we prove the nonexistence of two weighing matrices of‎ ‎weight 81‎, ‎namely $cw(88,81)$ and $cw(99,81)$‎. ‎we will apply two‎ ‎very different methods to do so; for the case of $cw(88,81)$‎, ‎we‎  ‎will use almost purely counting methods‎, ‎while for $cw(99,81)$‎, ‎we‎ ‎will use algebraic methods‎.

The Surface Energy Balance Algorithm for Land (SEBAL) is one of several remote sensing-based crop evapotranspiration (ET) models. One advantage that SEBAL has is its minimal requirement for ground-based weather data. However, its downside is that in the presence of advection it may underestimate ET. This is due to the use of a fixed evaporative fraction (EF) for the entire day. The EF value is ...

abstract by increasing the world population and more need to supply food, farmers attend to use of chemical fertilizers, organic manures and pesticides. also, applications of these agents without attention to their side effects, cause more problems to human health and environment. nitrate is one of the most important elements of organic manures, which leach through soil to surface and ground wa...

Crop model intercomparison studies have mostly focused on the assessment of predictive capabilities for crop development using weather and basic soil data from same location. Still challenging is performance when considering complex interrelations between dynamics under a changing climate. The objective this study was to test agronomic environmental flux-related set models. aim predict weighing...

Abstract Accurate simulation of evapotranspiration (ET) is essential to enhance efficient irrigation management in the maize field. Here, we evaluated performance four mathematical models for estimating ET maize. The based on surface resistance calculate from different vapor sources, which are Penman‐Monteith (PM) through “big leaf” model, Shuttleworth‐Wallace (SW) model distinguishing between ...