Browse on keywords: fertility Pacific Northwest
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5694. Rasmussen, P.E., D.E. Wilkins and C.L. Douglas Jr.. 1985. Annual-crop spring barley response to nitrogen, sulfur and phosphorus.. OR Agr. Expt. Sta. Special Report 738, p. 33-34.
Annual cropping is often possible where annual precipitation exceeds 14 inches. It is recommended on soils less than 4 ft deep since the soil profile normally is filled by a single winter's rainfall. Rotation of winter wheat with a spring cereal is often preferred to continuous winter wheat because weed control is easier and stubble more manageable. Fertilizer needs increase sharply under annual cropping because nutrient buildup by fallowing is eliminated and competition for nutrients by residue-decomposing organisms is more intense. In this study, nitrogen, phosphorous and sulfur response by spring barley was determined for annual-crop conventional and minimum tillage.
1688. Douglas, C.L.. 1983. Silicic acid and oxidizable carbon movement in a Walla Walla silt loam.. Ph.D Thesis, Oregon State Univ., Corvallis, OR. 75pp..
This study shows that use of ammonia fertilizers over the past 40 yrs, and particularly anhydrous ammonia in the past 15, has resulted in a more acid plow layer. The decrease in pH has caused soluble silica to leach out of the plow layer and led to cementation of the plow pan layer below 15 cm. The result is reduced water infiltration, increased water runoff and soil erosion, and increased soil water evaporation. Corrective applications of hydrated lime are explored. T: Mean silicic acid concentration in leachates from 15 cm soil layers as affected by long term N treatments. Long-term N and residue management effects on soluble carbon movement in four 15 cm layers. Soil pH and carbon addition effects on silicic acid concentration and transfer from the 0-15 cm layer.
3725. Koehler, F.E.. 1959. Fertilizer interactions in wheat producing areas of eastern Washington.. Proceedings, 10th Ann. Fert. Conf. PNW, Tacoma, WA, p.19-21.
The most frequently observed nutrient interaction in the wheat producing area of eastern Washington is that between sulfur and nitrogen under annual cropping. Where no sulfur was added, yields were increased by about 8 bushels per acre, and 30 lbs N/ac resulted in slightly better yields than did 120 lbs. When one lb sulfur was added per acre, yield increases from nitrogen were about 15 bu/ac, and again there was little difference between the effects of 30 and 120 lbs of N. However, where the sulfur rate was 10 lbs/ac, the yield increase with 30 lb N was 20 bu/ac and that with 120 lb N was 30 bu/ac. In no case did sulfur alone appreciably increase yields.
3735. Koehler, F.E.. 1961. Fertilizers and wheat quality.. Proceedings, 12th ann. Fert. Conf. Pacific NW, Salem, OR, p.73-78.
An overview of wheat protein, and relationships to N fertilizers. For soft white pastry type wheat grown in the Columbia Basin region of Oregon there was little increase in protein concentration until sufficient nitrogen had been added to give maximum yields. After this, further increases in nitrogen fertilizer rates caused rather marked increases in protein concentration. If high quality pastry wheat is to be produced, care must be taken not to use excessive amounts of nitrogen fertilizer. Yet, for maximum efficiency of production adequate nitrogen must be applied to obtain maximum yields. This means that the nitrogen supply must be rather carefully controlled for pastry wheat production. T: Average protein content of wheat as affected by nitrogen fertilizer.
3865. Leggett, G.E.. 1959. Relationships between wheat yield, available moisture and available nitrogen in eastern Washington dryland areas.. WA Agr. Expt. Sta. Bull. #609.
The purpose of this work is to demonstrate the relationships which exist between (1) available moisture and wheat yield and (2) available nitrogen and wheat yield. Using these relationships, it is possible to calculate the amount of fertilizer nitrogen necessary to obtain maximum wheat yield if the supply of available nitrogen in the soil and the amount of moisture available for the crop can be estimated. The results of 90 fertility experiments conducted on dryland wheat in eastern Washington during the period 1953-1957 were used to determine the relationship between wheat yield and available moisture. The results of 62 experiements were used to determine the relationship between wheat yields and available nitrogen. It is possible to calculate nitrogen fertilize recommendations from the results of soil tests for nitrate-nitrogen and available soil moisture by use of these relationships.
5632. Ramig, R.E., P.E. Rassmussen, R.R. Allmaras and C.M. Smith.. 1975. Nitrogen - sulfur relations in soft winter wheat. I. Yield response to fertilizer and residual sulfur.. Agronomy J. 67(2):219-223.
This study measured yield response of wheat to S applied with a range of N for the first crop and monitored residual S effects on yields of 3 subsequent crops. Significant N to S relationships were found. The first crop did not respond to S when N was deficient or optimal. Residual S increased straw yield in all crops and grain yield in 1 of 4 trials for the second crop, 3 of 3 trials for the third crop, and 2 of 2 trials for the fourth crop. Wheat response to residual S was influenced by N rates applied to the first wheat crop. High N and S fertilization resulted in early drought and lower yelds. Gradual release of residual S from recent organic matter apparently provided S at a rate adequate for efficient water use and maximum yield. T: Grain and straw yield response to S and N in first through fourth wheat crop following fertilization. The initial and residual effects of S on grain yield of wheat receiving optimum N.
5649. Rasmussen, P.E. and C.R. Rohde. 1988. Long-term tillage and nitrogen fertilization effects on organic nitrogen and carbon in a semi-arid soil.. Soil Sci. Soc. Am. J. 52(4): 1114-1117.
A 44 year experiment of wheat-fallow rotations in the Pacific Northwest. Main treatments were 3 primary tillage systems, one conventional and two stubble mulch. Subplots were 6 different N treatments. Organic N and C in the top 75mm of soil were 26 and 32% greater in the stubble mulch systems than the conventional system. Stubble mulch plots contained 245 kg more N/ha than the conventional plots. In all treatments 18% of applied N was incorporated into the organic fraction. N transformations were the same for stubble and conventional treatments. T: Organic N and C at different depths as effected by tillage method and N fertilization. Tillage and N effects on organic N in upper 225 mm of soil. Tillage and N effects on organic C in upper 225 mm of soil.
5659. Rasmussen, P.E. and C.R. Rohde. 1989. Soil acidification from ammonium-nitrogen fertilization in moldboard plow and stubble-mulch wheat-fallow tillage.. Soil Sci. Soc. Am. J. 53(1):119-122..
Change in soil pH in relation to applied N was determined for one conventional and two stubble-mulch tillage treatments. Acidifying effects were concentrated in the top 7 cm of the stubble-mulched soil, but distributed to 22 cm or more with moldboard plowing. The rate of pH decline was greater for moldboard plowing than stubble-mulching. T: Long-term N fertilization effect on pH in the upper 45 cm of soil under different tillage systems. Linear relationship between applied N and soil pH, as affected by tillage.
5684. Rasmussen, P.E. and R.R. Allmaras. 1986. Sulfur fertilization effects on winter wheat yield and extractable sulfur in semiarid soils.. Agronomy J. 78: 421-425.
Wheat yield in response to S was affected by yield level, intesity of cropping, and S accumulation in calcic horizons. At noncalcareous wheat-fallow sites with little S accumulation within 1.8 m of the surface, progressive downward movement of S occurred over 4 yrs. At an annual crop site with a calcic horizon, substantial yield responses to residual S occurred 25 yrs after application of 270-1570 kg S/ha. The highest fertilizer use efficiency was by fertilizing every 2nd crop with 14 kg S/ha when soil tests and yield data indicate a S deficiency. T: S and N fertilization effects on grain yield and S uptake by winter wheat. Extractable S in the upper 0.6 m of soil 2 and 4 yrs after S application. Cumulative plant uptake and extractable S in soil 1 and 4 yrs after S application. Extractable S in soil profile 25 yrs after S application ceased. Wheat yield response 1960-75, as affected by S applied between 1931-50.
5744. Rasmussen, P.E., R.E. Ramig, R.R. Allmaras and C.M. Smith.. 1975. Nitrogen - sulfur relations in soft white winter wheat. II. Initial and residual effects of sulfur application on nutrient uptake and N/S ratio.. Agronomy J. 67(2):224-228.
This study determined S and N uptake and distribution in soft white winter wheat fertilized with S in combination with deficient, optimum, and excessive N. Residual uptake from 17, 34, and 68 kg of applied S/ha was evaluated in 3 subsequent wheat crops receiving optimum N fertilization. S uptake and concentration in the first crop was proportional to the rate applied, but accumulated primarily in vegetative tissue when present in excess of the amount required for grain protein. Uptake from residual S was lower than from applied S. Grain yield responses to S were poorly correlated with S concentration or N/S ratios in tissue, because of inconsistancy of S accumulation in plant parts and the dominant effect of N on yield. T: Effect of N and S fertilization on S concentration and uptake at 3 stages of growth in a first wheat crop. Effect of residual S on grain yield and S concentration in grain and straw of second, third, and fourth crops. Relationship between S concentration in mature whole plants and grain yield receiving optimum N fertilization.