| 1901 - 932 páginas
...the same character in adjoining fields giving much smaller yields. The conclusion logically follows that on the average farm the great controlling factor...the exact nature of which is yet to be determined. It is not to be deduced from this that fertilizers do not frequently increase the yield of crops, but... | |
| United States. Office of Experiment Stations - 1903 - 1218 páginas
...of soil, or to some physiological or physical effect is not altogether clear." The authors conclude "that on the average farm the great controlling factor in the yield of crope is not the amount of plant food in the soil, but is a physical factor the exact nature of which... | |
| 1908 - 1062 páginas
...soil solution, which latter is the immediate source from which plants feed. From this it was concluded that on the average farm the great controlling factor in the yield (but not necessarily the quality) of crop is not the amount of plant food present, but a physical factor,... | |
| William Pickering Rutter - 1911 - 340 páginas
...is that low yields are usually related to the physical condition and characteristics of the soil ; the great controlling factor in the yield of crops...the exact nature of which is yet to be determined. Mr. Whitney, Chief of the Bureau APPLICATION OF FERTILIZERS 35 of Soils in the United States Department... | |
| R.J. Willis - 2007 - 316 páginas
...the same character in adjoining fields giving much smaller yields. The conclusion logically follows that on the average farm the great controlling factor...the exact nature of which is yet to be determined, (p. 63) The first review of the bulletin appeared in September 1903 in the Scientific American (Anonymous... | |
| 1904 - 874 páginas
...soil and the yield of crops." . . . "The conclusion logically follows that on the average farm tht, great controlling factor in the yield of crops is not the amount of plant food in the soil." . . . "It appears further that practically (theoretically) all soils contain sufficient plant food... | |
| 1904 - 874 páginas
...soil solution, which latter is the immediate source from which plants feed. From this it was concluded that on the average farm the great controlling factor in the yield (but not neces sariíy the quality) of crop is not the amount of plant food present, but a physical... | |
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