t 534 1 



Green-soiling or green-manuring^ i. c., ploughing in 

 of fresh vegetable manure, not only supplies nitrifiable plant- 

 food, but also mineral matters ; and it alters the physical 

 character of the soil, tending to make light soils heavier and 

 heavy soils lighter. By decomposition of vegetable and 

 animal manures (the latter decomposing more readily than 

 the former) COg is evolved which indirectly helps the 

 growth of crops by making soil particles soluble. The easi- 

 est way of supplying organic matter to soil as manure is to 

 grow some rapidly growing and tall leguminous crop in the 

 rainy season and to plough it in when it is in flower. 

 This not only draws up valuable materials from the subsoil 

 to the surface soil, but also adds to the stock of nitrates 

 in the soil which are not washed away so readily by rain 

 as when the land is bare or contains some short or thinly 

 growing crop. Of all Bengal plants suitable for green soiling 

 dhaincha (Sesbania aculeata) is the best. It is the most fast 

 growing and rank growing leguminous crop there is and as 

 it grows 6 or 7 ft. high in 3 months (June, July and August), it 

 is an excellent crop to cut and plough in at the end of August 

 in preparation-for October or November sowings. The Sibpur 

 Farm experiments with potatoes have given most unmistake- 

 able evidence regarding the high value of dhaincha as a 

 green-manure for the potato crop. It should be remembered 

 that the first stage of putrefaction with excess of moisture 

 gives rise to the evolution of some H 2 S gas, which is poison- 

 ous to plants. Aerification by constant cultivation from the 

 end of August to the end of October or middle of November 

 converts the sulphides into sulphates which are valuable as 

 plant food. Destruction of weeds and luxuriant plants grow- 

 ing by the edges of fields when they are in flower (/. e. before 

 Seeding) and using them as manure, serves also the purpose 

 of destroying a natural harbour of pests and parasites. Other 

 crops used in other countries for green-soiling are, mustard, 

 turnips, rape, tares, rye, lucerne, lupins, spurry, and clover, 



