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One of the most important nutrients for plant production is phosphorus (P). However mismanagement of fertilizer or manure can lead to P build‐up in surface soils and elevate P loss in runoff possibly resulting in accelerated eutrophication. Concern of excess P in runoff has increased interest in water‐soluble soil P and its use in determining potential for runoff P loss. Several variations of this procedure are currently in practice causing difficulty in comparing research findings. This study evaluated the effectiveness of several common variations of the water‐soluble P procedures. Water‐soluble soil P was analyzed for 10 soils using four different soil to solution ratios (1:2, 1:5, 1:10, 1:50) and four extraction times (10, 30, 60, and 900 min.). In addition, calcium chloride solutions (0.005 M, 0.01 M, 0.02 M) were compared to deionized water (DW) as extractant. The average amount of water‐soluble P increased with wider soil to solution ratio, whereas the extraction time had no effect on the ...

The Magruder plots are the oldest continuous soil fertility wheat research plots in the Great Plains region, and are one of the oldest continuous soil fertility wheat plots in the world. They were initiated in 1892 by Alexander C. Magruder who was interested in the productivity of native prairie soils when sown continuously to winter wheat. This study reports on a simple estimate of nitrogen (N) balance in the Magruder plots, accounting for N applied, N removed in the grain, plant N loss, denitrification, non‐symbiotic N fixation, nitrate (NO3 −) leaching, N applied in the rainfall, estimated total soil N (0–30 cm) at the beginning of the experiment and that measured in 2001. In the Manure plots, total soil N decreased from 6890 kg N ha−1 in the surface 0–30 cm in 1892, to 3198 kg N ha−1 in 2002. In the Check plots (no nutrients applied for 109 years) only 2411 kg N ha−1 or 35% of the original total soil organic N remains. Nitrogen removed in the grain averaged 38.4 kg N ha−1 yr−1 and N additions...

Wind machine tests were conducted in an Osoyoos, British Columbia, apple orchard on 6 spring nights during 1974. The magnitude of the temperature response observed was inversely proportional to the distance from the wind machine. It was determined that with temperature inversions of 5–7 C, some degree of frost protection could be provided over 3.2–3.6 h with a wind machine similar to that tested.

SynopsisThe data indicated partial dominance of gene action conditioning cold susceptibility in Canadian Variegated, Du Puits, and African alfalfas, and, using a model for tetrasomic inheritance, 17% of the variation associated with fall growth was attributed to additive gene action.

Crosses of early fall dormant ✕ early fall dormant,early dormant ✕ late dormant, and late dormant ✕ late dormant clones of Medicago sativa L. were planted in greenhouse flats and subsequently transplanted into the field. Seedling height, greenhouse regrowth, fall height (regrowth), spring height (regrowth), and percent winterkill were recorded. Correlation coefficients indicated that 25 to 36% of the variation in greenhouse regrowth could be associated with seedling height. Less than 5% of the variation in fall height and spring height could be associated with seedling height. A similar relationship was noted between fall height and spring height. This relationship, along with the range of types found in any seedling class, suggested that plants with good seedling vigor and good spring recovery could be selected from the early dormant ✕ early dormant group even though the tallest plants for fall height were only about half as tall as those in the early ✕ early or late ✕ late group. The segregation in the early ✕ late and late ✕ late group suggested that winterhardy plants with good seedling vigor, good regrowth, having tall fall and spring height could be selected.

SynopsisTen varieties and a mixture of alfalfa were grown at 60°, 70°, and 80° F. at 8-, 12-, and 16-hour daylengths for each temperature. Growth responses measured in cm. showed the greatest height differences at 60° F. and 12-hour daylength. At this temperature, the varieties and mixtures could be divided into three groups according to the magnitude of the variances. Varieties within each group were significantly different in height from varieties in other groups.