Vol. VIII. Xo. 179. 



THE AGRICULTURAL NEWS. 



69 



ONION CROP AT ANTIGUA. 



The following details in regard to plantings of 

 onions that have been made at Antigua in the present 

 season have been received from Mr. Thomas Jackson, 

 Curator of the Botanic Station in that island : — 



The area of the present season'.s (1908-9) onion crop in 

 Antigua is about 50 acres ; this area, is slightly less than 

 that planted last year, when 52 acres were grown. 



As already reported, onions are grown in this island 

 mostly as a catch crop previous to planting sugar-cane. 



The seed is sown in nursery beds, the soil of which is 

 well pulverized, and raised from S to 12 inches, the seed 

 being sown in drills which are fnun 4 to 8 inches apart. 

 From the.se beds the seedlings are transplanted into their 

 permanent position, which, in most case.s, is a cane field in 

 good tilth. 



During the year under review, this crop has suffered very 

 little from insect attacks. When the seeds were first planted, 

 some loss was caused by the deiiredations of ants. It was 

 found, however, that if a little kero.-ene oil was, on the first 

 two or three occasions, added to the water to be applied tr> 

 the plants — a wineglass full of kerosene being put to each 

 gallon of water and thoroughly stirred — these insects kept 

 away from the seed bed. 



As in previous years, the greater part of the seed for 

 this crop was imported from Teneriffe, through the Imperial 

 Department of Agriculture. The germination of the seed 

 was good. 



PEN MANURE. 



The continuous provision of a suitable supply of 

 humns is one of the chief problems of tropical agri- 

 culture, since in consequence of the rapidity with 

 ■which nitrification proceeds under the prevailing 

 climatic conditions, the quantity ])resent in the soil at 

 any given time tends quickly to disappear. The capacity 

 of a soil to retain moisture depends largely upon the 

 proportion of humus contained; decaying vegetable 

 matter, too, lighters heavy soils and imparts cohesion 

 to sandy soils. Its presence also is a condition without 

 which bacterial life will not flourish. On most estates 

 in the West Indies, the supply of pen manure seldom 

 reaches the quantity which could be utilized with 

 advantage, and consequenily it is a matter of the 

 utmost importance that the amount available should 

 be managed in such a way that the most is made out 

 of it. The fermentation of pen manure and the losses 

 of fertilizing constituents that frequently occur from 

 mismanagement were discussed in a recent number of 

 this journal (Agricidfaral iW/r.v, February 6 last, 

 p. 47). The following notes, which are taken from 

 an article on pen manure latel} published in the Fortn 

 Rico Hovticulturai Npwi< are given here, as supple- 

 menting the information contained in the previous 

 article : — 



The term ' farm manure ' includes dung from domestic 

 animals as well as waste materials from the farm. As the 

 average plantation keeps but few animals, the manure from 

 this source is of no great importance. But considering that 

 most soils in the West Indies are greatly benefited by pen 

 manure, it becomes an important question how to make the 

 most out of the small amount at hand. 



Dung is undigested forx:], and its content depends largely 

 on the kind of food consumed by the animal. The manure 

 from [lasture-fed cows is of little more value, as far as the 

 plant foods, potash, phosphoric acid and nitrogen are concerned, 

 than the guinea grass in the pasture. If cows or horses are 

 stall-fed, the dung will be more valuable because of the more 

 concentrated feed. The average composition of such dung in 

 the West Indies will probably be about 10 ft), nitrogen, 5 ft, 

 potash, and 5 lb. of phosphoric acid per ton, which compared 

 with the market price of plant foods in commercial fertilizers 

 would be worth $.3 to $5. This, however, is not a fair 

 estimate, because such manure is worth much more than the 

 actual plant food it contains when applied on the average 

 soil in the West Indies. 



Stable manure is valuable for the humus it contains as 

 well as for the bacteria it supplie.s. • The cultivated .soils lose 

 humus rapidly in this climate, and with the humus the 

 bacterial life disappears, which renders the soil inert and 

 unprofitable for cultivation. 



It seems to be well established that there is less los.s 

 when the manure is gathered up every morning, spread over 

 the land immediately and covered up, than if kept for 

 some length of time. This, however, is not practical when 

 there is but a small amount, and it is usually best to keep it 

 tinder conditions where it is least exposed to deterioration. 



The chief sources of loss are : fermentation, draining, 

 and leaching. Drainage can best be overcome by using 

 sufficient bedding in the stalls or the yard to absorb all the 

 liipiids. This beilding may be any absorbent material that 

 can be obtained cheaply, such as dry grass or leaves. 



Leaching cannot well be avoided except the yard is 

 covered. This it .seldom is in the West Indies, but considering 

 the value of manure and the comfort that it would aftbrd the 

 animals, it would undoubtedly jiay to cover the barn yard. 

 ( )n large sugar states in some of the West Indian islands 

 where hundreds of work-oxen are kept, and often fed for 

 long periods with cane tops and molasses, the manure is 

 usually left exposed to the sun and rain until it is of very 

 little value. In a covered yard where plenty of bedding is 

 used, the manure should he gathered up every twenty-four 

 hf)urs and added to the manure heap, which may conveniently 

 be placed at one end of the yard under cover. 



This method eliminates the two sources of loss, but the 

 third one, fermentation, is still to be guarded against. If 

 manure contains enough bedding to absorb all the liquids it 

 will be too dry in the pile, and dry fermentation will take 

 place. This can be avoided by frequently moistening the 

 heap with water and packing it down as firm as possible. If 

 the heap is large enough, it is well to let a few animals in to 

 tramp it down. In moistening the heap it is almost impossible 

 to avoid leaching, and it is well to have a tank in the ground 

 to catch the liquids running otf and leaching through the heap, 

 which can again be returned at the next watering. 



Lime should never be used in the manure heap as it 

 hastens decomposition and liberates nitrogen too fast. Sulphate 

 of lime or gypsum is very good because it absorbs ammonia. 

 Superphosphate is also good, and kainit is an exceptionally 

 good absorbent. It is therefore a good plan to add about 

 75 ft. of kainit and superphosphate to each ton of manure 

 in the heap, which not alouf helps to [ireserve the nitrogen, 

 but also increases the value 'if the manure to the extent of 

 the potash and phosphoric acid content in the ingredients 

 aflded, thereby making a mixture much more suited to the 

 recpiirements of the average crop. 



