Agronomy Journal

Cohen, O. P.; Strickling, E.

doi: 10.2134/agronj1968.00021962006000060001xpmid: N/A

Soil moisture measurements were made under alfalfa, tall fescue, and bermudagrass, receiving two levels of nitrogen fertilization, and bare fallow. The measurements were analyzed in order to determine the moisture use patterns of the various plants.

Ahenkorah, Yaw; Akrofi, G. S.

doi: 10.2134/agronj1968.00021962006000060002xpmid: N/A

The experimental layout, initial crop husbandry, preliminary girth measurements and yield results before and after the imposition of 2 years' shade and fertilizer treatments on the Amazon cacao Shade and Manurial Experiment (K2‐01) at Tafo are reported.

Harrington, James F.

doi: 10.2134/agronj1968.00021962006000060003xpmid: N/A

The equilibrium moisture contents of seeds of 35 kinds of grasses and legumes were determined for the seed moisture range of 13 to 4%. In comparison with the mean equilibrium moisture values of all seeds tested, the correlation coefficients for every kind of seed tested are highly significant, with r values of .95 to .99. This shows that although a given kind of seed may have a higher or lower moisture content than another kind at a given relative humidity, all kinds of seed tested showed essentially parallel changes in moisture content with changes in relative humidity, at least in the seed moisture range of 13 to 4%. A method is given for using the data presented in forecasting the equilibrium moisture percentage that each kind of seed will reach in a mixture of seeds in a sealed container.

Malcolm, C. V.; Stolzy, L. H.

doi: 10.2134/agronj1968.00021962006000060004xpmid: N/A

Coatings of latex and silicone were applied to potted sweet orange seedlings which were then grown either in the glasshouse or outside. Measurements of growth and moisture usage over a 20‐day period indicated that latex reduced moisture usage significantly in both situations. Growth was not significantly different for the treatment in any one environment. Leaf burn was less on latexcoated plants but distortion of the growing shoot appeared greater than in silicone‐coated and uncoated plants.

Blanchar, R. W.; Hossner, L. R.

doi: 10.2134/agronj1968.00021962006000060005xpmid: N/A

Corn (Zea mays) was grown on a Port Byron soil treated with either NH+4—N or NO−a—N and various rates of CaCl2·2H2O. The corn tissue was analyzed for Ca2+, Mg2+, K+, N, P, S, Cl, and NO−a—N. Equilibrium extracts of the soil were analyzed for Ca2+, Mg2+, K+, and electrical conductivity.

Flocker, W. J.; Yamaguchi, M.; Nielsen, D. R.

doi: 10.2134/agronj1968.00021962006000060006xpmid: N/A

Water evaporated from vertical columns of Yolo loam, 100 cm long, for 200 days at ambient temperatures of 10, 20, or 30C ± 1C. Distribution of soil water was determined by gamma‐ray attenuation at 5‐cm intervals, concomitantly with determinations of soil water pressure. Values of capillary conductivity based upon measured fluxes and hydraulic gradients are presented, along with values of diffusivity based upon fluxes and water content gradients.

Monson, W. G.; Reid, J. T.

doi: 10.2134/agronj1968.00021962006000060007xpmid: N/A

We determined in vitro digestible dry matter for two legumes (alfalfa and birdsfoot trefoil) and four grasses (smooth bromegrass, timothy, Reed canarygrass, and orchardgrass). Early‐ and late‐cut forage from each species was analyzed by a modified Tilley and Terry two‐stage digestion procedure. One‐third/two‐thirds mixtures were studied in all combinations within species and between each grass and legume. Certain mixtures of grasses and birdsfoot trefoil gave small, but consistent increases in dry‐matter digestibility over that calculated from the weighted mean of the mixture components. Dry‐matter digestibility and ad libitum intake of timothy and birdsfoot trefoil, separately and in mixtures, were determined in a feeding trial with sheep and steers. All forages in the in vivo studies had similar digestibilities. Average intake values of 117, 124, and 136% (timothy alone = 100) were obtained when forage fed was 33, 67, or 100% birdsfoot trefoil.

Jeffreys, R. A.; Wallace, A.

doi: 10.2134/agronj1968.00021962006000060008xpmid: N/A

A method was developed for the extraction of iron ethylenediamine di(ο‐hydroxyphenylacetate) (FeEDDHA) from plant tissue and the technique was used to study the absorption of FeEDDHA by plants. A published method for the extraction of FeEDDHA was modified in an attempt to eliminate plant components which interfered with the spectrophotometric determination of the iron chelate. The method which was developed involves the use of lead acetate and ammonium sulfate to precipitate interfering substances. The FeEDDHA is then extracted into η‐amyl alcohol.

Hojjati, S. M.; McCreery, R. A.; Adams, W. E.

doi: 10.2134/agronj1968.00021962006000060009xpmid: N/A

‘Coastal’ bermudagras(Cynodon dactylon (L.) Pers.) with and without supplemental irrigation on Cecil sandy loam fertilized with seven N:K treatments (224:224, 224:112; 224:37, 672:672, 672:336, 672:112, 1120:560 kg/ha per year) was clipped at 2‐, 4‐, and 6‐week frequencies. Analyses of the forage for TAC (Total Available Carbohydrates) as measured by the soluble plus hydrolyzable (2% v/v H2SO4) carbohydrates, showed that irrigation and fertilization decreased the percentage TAC but increased the total TAC production per hectare due to higher yields. Extending the clipping interval increased both the percentage and yield per hectare of TAC.

Robinson, R. G.

doi: 10.2134/agronj1968.00021962006000060010xpmid: N/A

Alaflfa (Medicago sativa L.), alfalfa‐brome (Bromus inermis Leyss.), red clover (Trifolium pratense L.), red clover‐timothy (Phleum pratense L.), sweetclover (Melilotus alba Desr.), and sweetclover‐timothy were maintained at Rosemount, Minn. under three management systems— removal of forage from the plots, mowing and leaving forage, and chopping and leaving forage. Within each management system, comparisons were made of one, two, and three cuttings per year. Uncut plots were included in each replicate. After 2 to 5 years of the management and cutting treatments, corn (Zea mays, L.) was grown for 2 years to determine residual effect of treatments on corn production using seven methods of land preparation.