Orchard Cover Crops in Delaware. 191 



.iority of the trees are two years old. Imt a few of tlie plums and pears are from 

 eight to ten years old. Ihe soil, a heavy clay loam, was in excellent condi- 

 tion when the seed was sown on July 22. and, as weather conditions were favor- 

 able for plant growth, tlie experiment started off most satisfactorily. The 

 amount of seed used was in many instances in excess of requirements. The 

 following discussion is a resume of the notes taken during the season. A part 

 of each plot was left unplowed in the spi-ing of ]0(i2. so as to get compara- 

 tive records of soil moisture on ground witli the cover crop turned under in the 

 Spring and on that with the cover crop growing until August. 



The chemical analyses of the cover crop plants and the soil moisture de- 

 terminations of the different plots were all made by Professor I'enny, chemist 

 of the Experiment Station. 



By Jul.v 20 the alfalfa and the red, mammoth, Egyptian and crimson clovers 

 were all up, the latter malcing the best showing. The rape was as good as 

 the crimson clover and the cowhorn turnips were better than the rape. The 

 plants of rye, soy bean and cow pea were two inches high. The hairy vetch 

 and velvet beans were not sprouted, except an occasional plant of the latter. 



Rye {Secalc cereal e, L.) — The seeding of this was very heavy, 130 pounds to 

 the acre. By the first of September a fine mat of plants covered the ground. 

 Two months later there was a growth of one foot : it was somewhat uneven with 

 lower leaves mostly killed by rust, but was still a good cover. The rye formed 

 an excellent winter protection to the ground and by April ] had made a new 

 growth of (j inches. It was from 114 to 314 feet high May 14 and a week 

 later it was mowed and spread over the ground as a mulch. The yield of the 

 green crop was at the rate of 7,(511 pounds per acre. Rye is not especially 

 rich in any of the elements of plant food, but does add a large amount of veg- 

 etable matter to the soil. Chemical analysis by Professor Penny, see table I, 

 .vhows that in the 7,6] 1 pounds of green matter there were 24.7 pounds of ni- 

 trogen. 39 pounds of potash and 11.4 pounds of phosphoric acid. There is also 

 some fertilizing value in the roots and stubble of the rye. From 1 bushel to 

 li-o bushels of seed per acre will be sufficient for cover crop purposes. 



Cowhorn tuniii) {Brassica Rapa, L.) — This is a variety of the ordinary 

 turnip, but is long instead of flat and grows half or more out of the ground. By 

 seedsmen it is often called the "long white." Eleven and one-half pounds of 

 seed were used per acre ; this is ten times the amount required as 2 pounds 

 of seed per acre is a most liberal allowance and in most instances 1 pound is 

 sufficient. The seed is so small that there is difficulty in spreading it uniformly 

 so the practice of mixing it witli fine dry soil was adopted and the whole lot 

 sown broadcast. The plants were so crowded that they thinned themselves 

 considerably. By September 1 they were from 2 to 12 inches high. Very little 

 growth was made after this date in the foliage and the fleshy roots could not 

 develop much because of the immense numbers struggling for existence. The.v 

 do not survive the winter and afford practically no protection to the ground 

 after midwinter. For cleaning up a piece of ground foul with weeds, etc., the 

 turnips heavily seeded, perhaps 2 pounds per acre, are most excellent. They will 

 smother out any other plant growth that we have seen competing with them. 



COMBINATK^NS WITH COWHORN TCRNII'S. 



Cowhorn turnips, crimson clorcr and hairy vetch. The cowhorn turnips 

 were used in combination witli other cover plants and where heavily seeded it 

 was with disastrous results to the other plants, except in the case of dwarf 

 Essex rape. At the following rate per acre the crops were sown, crimson clover 

 IG pounds, hairy vetch 90 pounds, and cowhorn turnips 41/, pounds. The 

 turnips not only choked out the clover and vetch, except at one end of the plot, 

 but also thinned out each otlier. A very little clover and vetch survived, but not 

 enough to afford much winter protection. To grow these plants together suc- 

 cessfully less seed must be used ; about 20 pounds of vetch, 8 pounds of clover, 

 and 8 ounces of turnips per acre ought to give good results. 



