648 EXPERIMENT STATION RECORD. [Vol. 43 



tioii with a nitrate-phosphate-potash fonmila 5:5:2.5 lbs. per tree per year, l.s 

 practically the same as that of the tillage-cover crop system without fertiliza- 

 tion. Under the tillage-cover crop system fertilization with nitrogenous plant 

 food gave a gain of 20.3 bbls. of apples, or a net cash gain of $50.'JG per acre 

 per year over no fertilization under the same cultural conditions. Under the 

 grass-mulch method of culture, fertilization with nitrogenous plant food gave 

 a gain of 37.8 bbls. of apples, or a net cash gain of $106.96 per acre per year 

 over no fertilization in the same section. 



Apples grown under the grass-mulch plan of culture were slightly smaller 

 but were finer in texture, firmer, higher in color, and superior in keeping quali- 

 ties to those produced under tillage. Also, the orchard work was performed 

 with cleanliness and comfort at all seasons of the year in the grass-mulch 

 section. 



There was little difference in results as to fruit production whether the 

 fertilizer was applied in circles beneath the outer extremities of the branches 

 of trees or over the entire tree squares of ground. The advantage of applying 

 the fertilizer all over the tree square, aside from increasing fruit production, is 

 that the vegetation of the orchard ground is increased, affording a greater 

 quantity of mulch material. This increase amounted to 1,650 lbs. per acre per 

 year, sun-dry weight, as compared with the yield of unfertilized plats. The 

 nitrate-phosphate-potash formula 5 : 5 : 2.5 lbs. per tree per year applied over 

 tree squares promptly developed, without seeding, a dense soil covering of 

 grasses and red and white clover where previously only mixed weeds, poverty 

 grass, and sedge prevailed. Broom sedge, by the annual nitrate-phosphate treat- 

 ment, was practically eliminated from the fertilized plats. Generally speaking, 

 pruning, spraying, and fertilization transformed this orchard from a disappoint- 

 ing farm encumbrance to a fruitful, vigorous, profitable plantation. 



The work on the other experimental orchard has been confined to orchard 

 rejuvenation by means of the grass-mulch system of culture combined with a 

 fertilization test and the necessary pruning and spraying. The results secured 

 confirm previous conclusions as to the importance of quickly available nitrogen 

 in successful orchard fertilization on thin, poor, upland soils of southern Ohio. 

 Phosphorus has also proved beneficial, but potash has given little or no retui-ns. 



Annual applications of 5 lbs. per tree per year each of nitrate of soda and acid 

 phosphate used in connection with a mulch of straw maintained by annual or 

 biennial applications of one bale per tree gave practically the same results as 

 the use of 10 lbs. per tree per year each of nitrate and phosphate applied evenly 

 over the tree squares without a mulch from outside sources. The greater 

 amount of fertilization, however, gave a gain of 2,066 lbs. per acre per year, 

 sun-dry weight, of grasses for mulch, as compared with the yield of inferior 

 grasses and weeds in the unfertilized plat. Annual applications of a 5:5: 2.5 

 lbs. per tree, nitrate-phosphate-potash mixture, used in conjunction with a 

 mulch of straw, gave a gain of 24 bbls. of apples per acre per year over a 

 2.5 : 5 : 2.5 lbs. per tree formula of the same fertilizers. 



On soil thai is not deficient in organic or vegetable matter, a liberal mulch of 

 straw alone will assist in producing effects similar to those following the appli- 

 cation of a moderately prompt-acting nitrogenous plant food, as such a nuilch 

 affords conditions under which there occurs a hastened liberation of nitrates 

 from the organic matter in the soil. On thin, poor, compact soils, the chief 

 ofiice of a mulch of straw or similar material is its helpfulness in conservation 

 of soil moisture. Under poor soil conditions where prompt results are sought, 

 mineral compounds of nitrogen and phosphorus are much more available than 

 animal compounds. With the tillage-cover crop system of orchard culture 



