ISSN:
1573-5036
Keywords:
Diffieultly available K
;
Exchangeable K
;
K uptake
;
Mica K
;
Regression Greenhouse
;
Sodium tetraphenylboron
;
Sorghum-sudangrass
;
Yield
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Bulk samples of 30 surface soils characterized in the National Cooperative Soil Survey of Louisiana were collected at the original sites and planted with sorghum-sudangrass in the greenhouse. The native K was exhausted by a total of four croppings. The available soil K was extracted with 1N NH4OAc 7.0 and 0.1N HCl while the difficultly available-K was extracted by 0.3N NaTPB (sodium tetraphenylboron). In addition, the mica content was estimated by differential dissolution. All soils except Dundee produced the greatest dry matter yield in the first crop with steadily decreasing production in the succeeding crops. The same pattern was shown in the K uptake. It appears that the first crop removed a large portion of the exchangeable K. There was a high degree of relationship between plant uptake of K and exchangeable K in the soils (r2=0.89**). Uptake by the subsequent crops was generally controlled by the K in the micaceous minerals (r2=0.89**). Since there was a high coefficient of determination between mica-K and difficulty available-K (r2=0.91**) one also finds that uptake of K by crops 2, 3 and 4 was also well correlated to difficultly available K (R2=0.94**). The uptake of K that was not originally in the exchangeable form was also highly related to difficultly available-K (R2=0.51**).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02374995
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