232 AGRONOMY [BoT. Absts., Vol. VII, 



use of fertilizer. Potassium fertilizer, however, increased, while phosphoric acid decreased, 

 the lime and magnesia content in the tops. Nitrogen gave variable results. Less than 50 

 kgm. nitrogen in tops, or 100 kgm. in roots, from 1 hectare denotes lack of nitrogen. Since 

 potassium influences production less, a definite amount taken up by the plant per hectare can- 

 not be given. Less than 14 kgm. phosphoric acid in the roots per hectare indicates a lack of 

 this nutrient, but for the leaves no definite figure is evident. Meteorological conditions so 

 influence the growth of beets that the nitrogen and potassium content does not lead to defi- 

 nite conclusions concerning fertilizer requirements of the soil. For P2O5 content the limit of 

 0.18 per cent in the roots and 0.40 per cent in the leaves can be set. For proof of the fer- 

 tilizer needs of a soil 2 different plots should be laid out, one fertilized with nitrogen, the 

 other with phosphoric acid and potassium. Conclusions may be drawn according to the 

 following rule: The soil is lacking in potash when in the tops the percentage of potash is less 

 than that of nitrogen. Phosphoric acid is lacking when the ratio N : P2O5 from the nitrogen 

 plot is greater than 5. Nitrogen is lacking when from the P2OS + K2O plot the ratio is less 

 than 100:35. The following conclusions were even more reliable: Potash is lacking when 

 it is less than 60 per cent of the nitrogen from the nitrogen-fertilized plot, and phosphoric acid 

 is lacking when PjOs is less than 40 per cent of the nitrogen.— C. E. Leighty. 



1566. Nielsen, H. B. Potato certification in California. Monthly Bull. California State 

 Commission Hort. 8: 285-287. 1919. 



1567. Pfeipfer, T. Die Bedeutung der sogenannten Schutzstreifen bei Feldversuchen 

 und die Wahrscheinlichkeitsrechnung. [The significance of the so-called protection strips 

 in field trials and the probability calculation.] Fiihlings Landw. Zeitg. 68: 412-419. 1919.— 

 A criticism of the conclusions of Schneidewind and his associates regarding the use of un- 

 planted and untreated strips between test plots in field experiments, in which it is stated 

 that plots with unplanted division strips show too high yields, that in consequence the effects 

 of manurial treatments are minimized and that by keeping the fertilizer distribution within 

 the outside drill rows of the plot there would be no noticeable effect upon neighboring plots 

 and interspaces might better be omitted. It is shown that plants draw nourishment from 

 the unplanted division strips, that adjoining and differently treated plots do affect each other, 

 and that in field trials involving comparisons of different treatments division spaces should 

 be used but that these should not be left unplanted. It is also held that the probable error 

 calculation can be used to good advantage and should always be employed.— A. T. Wiancko. 



1568. Pitt, J. M. Lucerne on the coast. The central coastal districts. Agric. Gaz. New 

 South Wales 31: 381-384. 1920.— It is claimed that the alluvial soils bordering the rivers in 

 this region are admirably suited to alfalfa. The Hunter River has long been famed for its 

 enormous output of hay and seed of the Hunter River strain. Formerly, stands 12-20 years 

 old were not uncommon, but now the profitable life averages from 4 to 7 years. This is attrib- 

 uted to various causes, such as inferior seed, decrease of humus, sowing at wrong season, 

 poor preparation, cutting too often and grazing too closely. Cultural instructions are given 

 in detail. Autumn seeding at the rate of 15-20 pounds per acre has proved most satisfactory. 

 Instructions are also given on cutting, curing, and grazing. Top dressing with 2 cwt. of 

 superphosphate applied in the early spring and harrowed in has proved very beneficial.— 

 L. R. Waldron. 



1569. Rao, U. Vittal. Habit in sugar canes. Agric. Jour. India 15:418-424. 1920.— 

 A report on the straightness of sugar canes as revealed by pot experiments, station records, 

 and as influenced by suitable crossing. Straight canes are preferred by factories and by 

 cultivators, partly because lodged canes contain less cane sugar and more glucose.—/^. M. 

 Schertz. 



1570. Reynolds, B. A. Sterilize the fencerow and reduce next year's losses. Monthly 

 Bull. Dept. Agric. California 8: 595-599. 1919. 



