Nitrogen and phosphorus are key limiting nutrients in teff [Eragrostis tef (Zucc.) Trotter] production. The crop is particularly sensitive to N fertilization, and as a result forage and grain yields are influenced. We conducted four site‐year studies to determine N and P requirement of teff grown under a dryland production system. Studies were located in central Oklahoma. Treatments included nine N and P combinations. Commonly grown varieties ‘Quick‐E’ and ‘Tiffany’ were used in 2009 and 2010, respectively. Experiments were arranged in a randomized complete block design with three replications. Data were subject to statistical analysis using Statistical Analysis Software (SAS). Analysis of variance (ANOVA), orthogonal polynomial or paired contrasts and non‐linear regressions were used to determine the effect of treatments on teff forage and grain yields and quality. Results showed that for central Oklahoma, optimum fertilizer N rate was 67 kg/ha which corresponded with a 1.1 Mg/ha yield goal. Forage crude protein increased with N rate. In addition, N and P influenced some teff mineral and forage quality parameters such as Ca, Fe, acid detergent fiber, and crude protein. Recommendations provided here will serve as a benchmark for N and P fertility guidelines for producers in Oklahoma and semi‐arid regions who want to grow teff in a niche market.

One of the major problems that potentially hinders the use of foliar fertilization as a tool to improve nutrient use efficiency is the lack of effective formulations. A phosphite based product, Nutri-phite (3% N, 8.7% P, and 5.8% K) was used as model phosphite formulation for foliar application in winter wheat (Triticum aestivumL). Five field trials were established in the fall of 2009 and 2010 at Perkins, Perry, and Morrison, OK. Treatments encompassed the application of nitrogen (N) at 100 or 75% of crop need and phosphorus at 100 (P 100%) and 80% (P 80%) sufficiency with and without Nutri-phite. Nutri-phite was applied at one and/or two stages of wheat; GS 13 to 14 and GS 49 to 53 at the rate of 433 and 148 g ha−1P and N, respectively. Grain yield was increased by Nutri-phite treatments, especially at Morrison. Grain P concentration of plots treated with two applications of Nutri-phite ranged from 13 to 55% more than the nontreated and standard NP received plots at Perkins in 2009/10 and Perry in 2010/11. Grain P uptake was increased due to application of Nutri-phite at Perkins in 2009/10 and Morrison and Perry in 2010/11. Combined over three year-locations, Nutri-phite increased grain P concentration by 11.6%. The higher grain P concentration of plots treated with Nutri-phite compared to the other treatments clearly demonstrates its potential in improving P status of wheat grain.

No abstract