SOILS FERTILIZERS. 627 



mineral fertilizers for sandy soils, and intensive versus ordinary methods of 

 cultivation. 



Among the conclusions it is noted that sea mud gave better results in com- 

 bination with barnyard manure than with mineral fertilizers. Intensive culti- 

 vation, consisting of deeper plowing, better seed-bed preparation, and the use 

 of larger quantities of manure, increased the yield, in some cases as much as 

 40 per cent. 



Experiments on the effect of straw on the action of the nitrogen of green 

 manures, K. Stormer (FiihUnff''s Landiv. Ztg., 60 {1911), No. 6, pp. 1S5-19S; 

 abs. in Inteimat. Inst. Agr. [Rome], Bui. Bur. Agr. Intel, and Plant Diseases, 

 1911, No. 4, PP- 822, 823). — In the series of pot and field experiments hei'e re- 

 ported on heavy and light soils the addition of straw to green manure raluced 

 the efficiency of the nitrogen of the latter during the first year, but the results 

 were better the second year. The use of straw alone reduced the yield, and the 

 finer the straw the greater the reduction. Treatment during the second year 

 with carbon bisulphid of soil to which straw had been applied nearly doubled 

 the yield. 



Cooperative fertilizer experiments with corn, cotton, rice, caulifl.ower, 

 peanuts, onions, tomatoes, and potatoes, 1908-1910, G. S. Fraps (Texas Sta. 

 Bui. 138, pp. 5-71). — "This bulletin contains the results of 37 cooperative ferti- 

 lizer experiments on corn, 21 on cotton, 7 on rice, 1 on cauliflower, 2 on peanuts, 

 1 on onions, 2 on tomatoes, and 13 on potatoes, carried out ... to ascer- 

 tain the fertilizers adapted to various crops on Texas soils, under Texas con- 

 ditions, and also to ascertain the relation between chemical composition, pot 

 experiments, and needs of soil as shown by fertilizer experiments. 



"Dry weather interfered to some extent with the experiments on corn. 

 Acid phosphate at the rate of 200 lbs. per acre increased the yield in 31 of the 

 37 experiments. The increase averaged from 390 to 440 lbs. per acre of ear corn 

 in the three years. Seventeen of the 37 experiments gave increases with cot- 

 tonseed meal, which sujiplies nitrogen mostly. The average increase was 

 greater with 120 lbs. per acre than with GO lbs. per acre. Corn fertilized with 

 cottonseed meal appears to sufl:"er more quickly from drought than that fertilized 

 with acid phosphate. Potash increased the yield in 12 of the 37 experiments. 

 Where it was needed, it had a considerable effect on the yield. The soils which 

 gave increased yields with cottonseed meal contain on an average less nitrogen 

 than those which did not give increases. When less than 10 parts per million 

 active phosphoric acid was present 2 soils gave increases with acid phosphate 

 and 1 did not, but it is believed the sample did not represent this soil. The 

 average yield without fertilizer on these 2 plats is 4.5 bu. per acre. The average 

 c8rn possibility in pot experiments, based on phosphoric acid removed, is 4.5 bu. 

 per acre. Six of 9 soils containing 10 to 20 parts per million of active phos- 

 phoric acid gave increases with phosphate, and the average yield without ferti- 

 lizer is about 17 bu. per acre. The average corn possibility based on pot ex- 

 periments is 12.5 bu. per acre, maximum 31 bu. Four soils containing 20 to 30 

 parts per million of active phosphoric acid all responded to phosphate, and the 

 average yield without fertilizer was about 24 bu. per acre. The average corn 

 possibility from pot experiments was 20.8 bu. per acre, maximum 36 bu. There 

 was a relation between the average production of corn by the soils and the 

 quantity of active phosphoric acid in them. 



" In 17 of 21 cooperative experiments on cotton acid phosphate increased the 

 yield. In 15 of the 21 experiments cottonseed meal increased the yield. Cotton 

 fertilized with cottonseed meal does not suflier so much from drought as does 

 corn fertilized with it. In 10 of the 21 experiments potash increased the yield. 

 It would appear from these experiments that potash is more likely to be of 



