64 Journal of the Department of Agriculture. 



It is said that for mature vineyards ivell rotted manure is prefer- 

 able to fresh manure, as the latter causes too rank a growth of leaves 

 and shoots. Eotted manure will usually contain more plant-food 

 per ton than fresh manure, though in the process of rotting a con- 

 siderable amount of humus and plant-food is lost (2 tons of fresh 

 manure yield approximately 1 ton of rotted manure). Fresh manure 

 is said to be very useful for young nursery stock. 



Green Manure. 



A green manure is a crop seeded in between the vines, and subse- 

 quently ploughed under. It is grown purely for the purpose of 

 improving the soil, not for obtaining any harvested product. Green 

 manuring should find a place in all kinds of farming, whether grain, 

 fruit, or wine, especially where the soils are light, of poor fertility, 

 and deficient in humus. In this country, as far as vineyard lands 

 are concerned, the practice is as yet almost untried. 



Any kind of crop may be used for green manuring, but the best 

 crops for this purpose are the legumes, such as peas, beans, lupins, 

 clover, etc. Legumes contain relatively more nitrogen than other 

 crops, and they obtain a considerable portion of this nitrogen from 

 the atmosphere, through the agency of bacteria which live in the 

 nodules on the roots of the plants. The poorer the nitrogen-content of 

 the soil is the greater will be the proportion of nitrogen taken from 

 the atmosphere. Thus we have a ready means of adding nitrogen to 

 the soil in an inexpensive, yet very useful form, and at the same 

 time a large amount of valuable humus is also added. 



In the main viticultural areas, field peas would probably form 

 the best green manure, as the crop is succulent, not too fibrous, and 

 decays rapidly in the soil. A good growth of peas in the vineyard 

 would probably contain at least 100 lb. nitrogen per morgen (roots 

 included). This would correspond roughly to a green growth of 

 about 5^-6 tons per morgen. It has been estimated that the crop 

 obtains from two-thirds to three-fourths or more of its total nitrogen 

 from the air (provided the soil is deficient in nitrogen), i.e. in the 

 above case, say, 75 lb. of nitrogen. Thus by ploughing under this 

 crop we enrich the soil to the extent of 75 lb. of nitrogen and several 

 tons of humus per morgen. The market value of the nitrogen alone 

 to-day would be over £4. 10s. 



Where green manuring is practised, the crop must be ploughed 

 under as early as practicable, so that it will not interfere with the 

 growth of the vines, and also that it may have a chance to decay 

 in time to yield nitrogen to the vine roots. 



The seed must be sown as early as possible after the first rains 

 in April, so that the crop may be ploughed under at the end of July 

 or early in August. If the ordinary green or white field-pea be 

 sown early in April, it will be in full bloom toward the end of July, 

 and can then be turned under. After two to three w-eeks the crop 

 as a rule will have rotted to such an extent that the vineyard can 

 be cross-ploughed or cultivated (i.e. the rotting material will not 

 impede the implements). The best time for ploughing the crop under 

 is when it is in full bloom; but should the rains be late so that the 

 peas cannot be sown until May it may be advisable to turn the crop 

 under before it is in full bloom. Unless the season is exceptionally 

 late, the green manure crop should never be ploughed under later 



