Orchard Cover Crops in Delaware. 193 



Crimson clover {Trifoliiim incarnatum, L.) was heavily seeded at the rate 

 of 37 pounds per acre and gave a good stand except in spots where heavy rains 

 washed out or covered up the young plants. On this account the stand was 

 uneven. The growth was excellent ; 9 inches by November 1. making a splendid 

 protection to the soil. Tlie w'nter was severe and most of the clover killed one 

 before spring. This winter-killing of crimson clover was quite common through.- 

 out the northern part of the State in 1901-2. New growth started the last of 

 April, but there were not enough plants left for a successful spring cover. The 

 few which remained were from 6 to 18 inches high and in bloom May l.j. 

 Crimson clover is the great soil enricher and is often used as the standard 

 with which to compare other crops for this purpose. The following rec'U-ds 

 were made from the crop just mentioned. The seed was sown July 22 iiud 

 the samples were taken November 20. The four months' growth of green t^ps 

 per acre weighed 18,800 pounds, nearly 91^ tons; the roots to a depth of 12 

 inches weighed 413 pounds, air-dry weight (see table I). In the tops and roots 

 were 131 pounds of nitrogen. 88 pounds of potash and oi pounds of phosphoric 

 acid. To purchase these amounts of plant food in commercial fertilizers 

 per acre of soil would entail a greater expense than the fruitgrower would care 

 to incur. Besides this plant-food, the addit on of such a large amount of veg- 

 etable matter, or humus, to the soil is most beneficial. 



Crimson clover was first grown in Delaware by Mr. J. G. Brown, Sr., near 

 Wyoming, in 1885 or 1886*. Mr. Brown grew large areas of clover in his or- 

 cliards for ensilage and for seed. He soon noticed that the production of 

 clover seed injured the orchards, and this practice was abandoned. About ISSS. 

 a few other fruitgrowers began using the clover as an orchard cover crop and 

 have continued to use It with excellent results up to the present time. 



Red clover and mnmmotli clover. — These were seeded at the same rate as 

 the crimson clover, namely, 37 pounds per acre. About 15 pounds of seed per 

 acre is the usual amount used for these three clovers. The red and mam- 

 moth clovers were side by side and did equally well, so they will be considered 

 together. The stand was good, but growth was unequal ; it made a good mat 

 from 3 to 10 inches thick by November 1. Both clovers came through the 

 winter in good condition, and in this respect eclipsed the crimson clover. By 

 the end of March they had made a new growth of 2 inches and G weeks later 

 a heavy matted growth of 12 to -8 inches. The results were most satisfactory 

 and encouraging, and were as good as could be desired. (See Plate IV. A. 

 red clover). 



The fall growth of tops of the red clover was not so heavy as that of the 

 crimson clover, being only 6,909 pounds in 4 months, against 18.800 pounds of 

 the crimson. The root growth in the same time was three times as much for the 

 red as for the crimson clover, namely, 1,212 pounds, air-dry weight. In total 

 weight of tops and air-dry roots the crimson clover yielded a little more than 

 2 1-3 times as much as the red clover. (See table I). The red clover seems 

 to be richer than crimson clover pound for pound in nitrogen and potash, for 

 with less than haif the total weight of plants it yielded more than three-fourths 

 as mtich nitrogen and more than three-fifths as much potash. 



Egyptian Clover (Trifolium alexandrimum, L.) — This was tried, but was 

 most unsatisfactory. Although heavily seeded, 37 pounds per acre, there was 

 a very thin stand from the start. The few plants alive November 1 were from 

 6 to 15 inches high ; they were killed by heavy frosts a little later. It i.s 

 not hardy enough for cover crop purposes here. 



Alfalfa (..ledicago sativa, L.) — On the heavy clay at the Experiment tSation, 

 alfalfa does exceedingly weil. In six weeks from sowing the seed. 37 pounds 

 per acre, the plants were from 6 to 12 inches tall and the stand was gootl. 

 By November 1 much of the growth was 18 inches high. It made an excellent 

 cover and survived the winter in fine condition. Fall sowing of alfalfa is no 



♦Information kindly furnished by Mr. and Mrs. F. M. Soper, Magnolia. 

 HOR. 13 



