Browse on keywords: fertility CO
Search results on 10/17/18
26. Lerch, R.N., K.A. Barbarick, D.G. Westfall, R.H. Follett, T.M. McBride, and W.F. Owen. 1990. Sustainable rates of sewage sludge for dryland winter wheat production. 2. Production and income.. J. Production Agric. 3:66-71.
A sewage sludge application rate of 3 T/ac on hard red winter wheat increased gross income by an average of $45/ac/year compared to wheat grown with the typical 50-60 lb fertilizer N/ac. This was primarily due to premiums paid for higher grain protein. Grain levels of P an Zn were increased by sludge application, while levels of Cd, Ni, and Pb have remained low.
82. Lerch, R.N., K.A. Barbarick, D.G. Westfall, R.H. Follett, T.M. McBride, and W.F. Owen. 1990. Sustainable rates of sewage sludge for dryland winter wheat production. 1. Soil nitrogen and heavy metals.. J. Production Agric. 3:60-65.
This study determined that a 3 T/ac rate was the maximum allowable for the dryland wheat-fallow system. The sludge significantly increased heavy metal concentrations in the soil at all loading rates. Increased ntirates in the root zone resulted from a 12 T/ac sludge rate, compared to a 50 lb N/ac fertilizer application.
1257. Cerrato, M.E. and A.M. Blackmer. 1990. Comparison of models for describing corn yield response to nitrogen fertilizer.. Agron. J. 82:138-143.
The study compares and evaluates several models (linear-plus-plateau, quadratic-plus-plateau, quadratic, exponential, and square root) commonly used for describing corn response to N fertilizer. All models indicated similar maximum yields, but there were marked discrepancies among models when predicting economic optimum rates of fertilization. Statistical analysis indicated that the most commonly used model, the quadratic model, did not give a valid description of the yield responses and tended to indicate optimal rates of fertilization that were too high. The quadratic-plus-plateau model best described the yield responses.
2221. Goldstein, Walter A.. 1986. Alternative crops, rotations, and management systems for dryland farming.. Ph.D. dissertation, Agronomy and Soils, WSU.
This work covers a number of research areas, including the use of edible white lupine as an alternative crop, the use of black medic in rotation with spring peas and winter wheat (the PALS concept), performance of winter wheat as influenced by rotations, fertilization, and fumigation; rotational effects of medics; wheat interference with weeds; costs and returns of alternative systems; comparison of agronomic effects of conventional, organic, and biodynamic management. The PALS (perpetuating alternative legume system) concept was field-tested using a pea + medic - medic GM - winter wheat rotation with limited inputs of agrichemicals and tillage. This system was more economic using market prices of commodities at both a low and high yield level. With government support prices, the PALS system was competitive in the low yield situation, but not the high. Rotational effects appeared to suppress weeds in wheat with the medic compared to a continuous cereal system.
2480. Harris, G. and O.B. Hesterman. 1990. Quantifying the nitrogen contribution from alfalfa to soil and two succeeding crops using N-15.. Agron. J. 82:129-134.
This study quantified the N contribution from different alfalfa plant parts to a subsequent corn crop, various soil fractions, and a 2nd year spring barley crop. Corn recovered 17 and 25% of the alfalfa applied N-15 on a loam and sandy loam soil respectively. Alfalfa N-15 remaining in soil averaged 46% of the initial input. Most (96%) of the alfalfa N-15 remaining in soil was recovered in the organic fraction, with microbial biomass accounting for 18% of this recovery. More N-15 was reocvered by corn and in soil from alfalfa shoots than roots/crowns. More was recovered from a spring incorporation than a fall incorporation on the loam soil. Only 1% of the alfalfa N-15 from the original application was recovered by a 2nd year spring barley crop.
4077. Mason, J.L. and J.E. Miltimore. 1959. Increase in yield and protein content of native bluebunch wheatgrass from nitrogen fertilization.. Canadian J. Plant Sci. 39:501-504.
Native bluebunch wheatgrass in Okanagan Valley (11" precip.) showed marked response to nitrogen fertilization. Dry matter production doubled with 60N added as ammonium nitrate, protein increased from 3.9 to 6.2 %. Fertilizer also increased ground cover by the desirable grasses.
5181. Peterson, P.P.. 1919. Soil and climatic factors in relation to crop production on the Palouse.. ID Agr. Expt. Sta. Bull. #118.
8 rotations with N, P, K trts; clear response to N - 3 bu/ac on wheat at 200 #/ac NaNo3; manure response = 6 bu/ac; wheat yielded same after potatoes and fallow than peas or corn; made the most money with wheat/oats/peas ($51/ac/yr); ave. oat yield 1916 = 70+ bu/ac, 1918 = 26 bu/ac. Wheat, oats more affected by drought than corn or potatoes; this is the first mention of statistical methods. T: fertilizer response, rotation X net return.
5396. Jackson, G.D. and J.R. Sims. 1977. Comprehensive nitrogen fertilizer management model for winter wheat.. Agron. J. 69:373-377.
6301. Singh, R.A., O.P. Singh and M. Singh. 1976. Effect of soil compaction and nitrogen placement on weed populations.. Plant and Soil, 44:87-96.
Field experiements showed that soil compaction did not affect wheat yield significantly under rainfed conditions. Weed population was significantly reduced due to soil compaction. Compaction decreased total moisture use and increased water use efficiency. Weed population was not affected due to nitrogen placement. Under rainfed conditions, deep placement of nitrogen was important for increasing the efficiency of fertilizer as well as water utilization by wheat crop.
6647. Steel, S. and D. Smith. 1990. Farming from the ground down.. Farm Journal (mid-January).
Discusses Terry Holsapple farming system in Illinois. Both P and K levels have risen several years after the last application of commercial fertilizer.