Abstract

The fertilizer requirements of crops are ascertained by (a) tield experiment- ation and (b) soil analysis. The author has been experimenting with a new method promising to be cheaper and quicker than the field experiment and mure accurate and reliable than soil analysis. Field experiments are accurate but slow, and costly and beset with a number of limitations: (1) The field should be uniform, (2) The field should be large enough to accommodate the desired number of repetitions of the verious treat- ments and (3) The experiment should be conducted for a number of years for eliminating residual effects of previous fertilization and seasonal effects and for studying the after effects of the treatments themselves. Soil analysis is cheap and quick, but the results obtained are vague. Various methods of determining the soluble plant food in the soil are in vogue. The results obtained need not necessarily represent what actually the various crops could extract from the different soils. Abstract of the first part of the article. Ed.]

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