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The spacing of corn in the west central Great Plains 全文
1937
Brandon, J.F.
A 2-year rotation of corn and winter wheat at Akron, Colo., was used to determine the effect of different spacings of corn on the yield of the corn and the following wheat crop. Twelve crops of corn were grown from 1924 to 1935, inclusive, and nine crops of winter wheat. Failure to obtain stands through winter-killing and insect injury accounted for the loss in winter wheat crops. The highest 12-year average yield of ear corn was 13.3 bushels per acre for 24-inch spaced plants in 44-inch rows. This spacing is recommended for grain production for conditions similar to those found at Akron. The 12-year average yield of 9.2 bushels per acre of ear corn from the double-spaced rows, was 28% less than the average for five spacings in the 44-inch row plats. The highest total corn yield, 3,038 pounds per acre, was from the 12-inch spacing in 44-inch rows. The yield from the 18-inch spacing was only a little lower. From 12 to 18 inches in 44-inch rows is recommended as a spacing for silage production in this locality. Corn seeded 30 to 36 inches apart in 44-inch rows averaged about 30% ear corn by weight. That seeded 12 to 18 inches apart in 44-inch rows averaged about 20% ear corn. That seeded 24 inches apart in 44-inch rows averaged about 25% ear corn. The highest average yield of winter wheat for grain was 12.8 bushels per acre obtained from double-spaced row corn land. This was 2 bushels per acre higher than the average of the five spacings in 44-inch rows. There was a loss in ear corn production of 3.6 bushels per acre when the double-spaced row plat was compared with the average for the five spacings in the 44-inch rows. The gain in wheat yield did not more than compensate for the loss in corn. Planting corn in double-spaced rows decreased yields markedly in years of good production and did not increase the sureness of production in poor years. There was not a single adverse year when the yield of double-rowed corn equalled that of thin-spaced corn in regular width rows. The greatest total production of ear corn and wheat grain was obtained from land where corn plants were spaced 24 inches apart in 44-inch rows. The greatest total weights of corn and wheat (grain, stover, and straw) were obtained from the 12-inch spaced corn in 44-inch rows
显示更多 [+] 显示较少 [-]The wheat meal fermentation time test with special reference to its reliability as a measure of quality in soft winter wheats 全文
1937
Cutler, G.H. | Worzella, W.W.
Statistical studies were made on comparable data derived from fermentation time test, protein content, and baking tests on (a) 12 soft and semi-hard varieties of wheat grown at three locations in Indiana in the four seasons of 1930 to 1933, inclusive, and on (b) 12 typical soft wheat varieties grown at Lafayette, Indiana, for 4 years, 1931 to 1934, inclusive. The analysis of the data from these tests revealed that the fermentation time test accurately appraised the gluten quality of the wheats studied. It gave consistent results one year with another at all locations. Much spread in quality was obtained among the soft wheat varieties. Small differences were found in protein content and loaf volume in the soft wheats studied. Loaf volume data, especially, were inconsistent and erratic. On the basis of these analyses, together with the favorable results reported by a large number of investigators, the fermentation time test may be regarded as a reliable guide in measuring the relative gluten quality of soft winter wheats.
显示更多 [+] 显示较少 [-]A comparison of the numbers of two species of Rhizobium and ammonia-oxidizing organisms in variously treated Iowa soils 全文
1937
Thorne, D.W. | Brown, P.E.
The approximate numbers of Rh. meliloti, Rh. trifolii and ammonia-oxidizing organisms in variously treated soils on the Agronomy farm of the Iowa Agricultural Experiment Station were determined at several different periods. The logarithms of the numbers of Rh. meliloti and Rh. trifolii in the soils studied had a highly significant correlation. The logarithms of numbers of Rh. meliloti and nitrite-forming organisms in the variously treated soils cropped to the 3-year rotation of corn, oats, and clover were highly significantly correlated. In similarly treated soils cropped to a 5-year rotation of corn, oats, red clover, winter wheat, and alfalfa, a highly significant correlation between these organisms was also noted. The correlation between the logarithms of numbers of these organisms in soils cropped only to corn and oats was much lower, being just significant. The correlations between the actual numbers of organisms showed a similar trend to those found between the logarithms of numbers. The presence of legumes in a crop rotation seems to promote a more stable flora of the organisms investigated. The ammonia-oxidizing organisms and the legume bacteria studied showed similar responses to fertilizer treatments. Greater fluctuations were observed, however, in the numbers of legume bacteria. The ammonia-oxidizing organisms reached their maximum numbers in the spring or early summer. The alfalfa and red clover bacteria showed no consistent seasonal fluctuations.
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