In this research effects of active toothed coulter on planter penetration in semi-dried soils covered with previous wheat (Triticum aestivum) residue was studied. Therefore, effects of three levels of speed ratio (coulter peripheral speed/tractor forward speed; 1.22, 2, 3) at two previous residue levels (baled and non-baled) and two modes of planter attachment (with and without row cleaner) on ...

Nitrate losses from subsurface tile drained row cropland in the Upper Midwest U.S. contribute to hypoxia in the Gulf of Mexico. Strategies are needed to reduce nitrate losses to the Mississippi River. This paper evaluates the effect of fertilizer rate and timing on nitrate losses in two (East and West) commercial row crop fields located in south-central Minnesota. The Agricultural Drainage and ...

To better understand cover crop benefits and receive nitrogen scavenging credits for cropping, farmers need simple robust methods of predicting biomass production. A new regulation focused on improving management over 200,000 ha irrigated land in the central coast California motivated us to evaluate if shoot length rye (Secale cereale L., ‘Merced’) triticale (× Triticosecale Wittmack, ‘Pacheco’...

In this paper, we investigate the asymptotic theory for U -statistics based on sample spacings, i.e. the gaps between successive observations. The usual asymptotic theory for U -statistics does not apply here because spacings are dependent variables. However, under the null hypothesis, the uniform spacings can be expressed as conditionally independent Exponential random variables. We exploit th...

We investigate the eigenvalue spacing distributions for randomly generated 4-regular Cayley graphs on SL2(Fp) by numerically calculating their spectra. We present strong evidence that the distributions are Poisson and hence do not follow the Gaussian orthogonal ensemble. Among the Cayley graphs of SL2(Fp) we consider are the new expander graphs recently discovered by Y. Shalom. In addition, we ...