PASTURE CULTURE 37 



filled with water.133 That such seeds can live for a long time submerged in water., 

 gives some indication as to how long they might lie dormant in the soil before 

 germinating. More recent experimental work tends to support these earlier 

 observations. 13* What evidently happens is that a great many seeds are lying 

 dormant in the soil and that a few of them germinate every year. If fertility 

 conditions are favorable these few plants make an extremely rapid, spreading 

 growth. One single plant under favorable circumstances may spread out in a 

 radius of from two to three feet in one season's growth. The limiting factor to 

 growth may be the lack of one or more of the fertilizer elements, or it may be 

 lack of moisture; but if these factors are eliminated, this remarkable "spon- 

 taneous" growth of natural white clover invariably results. The seeds of natural 

 white clover appear to have been universally distributed over the whole of New 

 England and the sudden appearance of this species can occur almost anywhere. 



Top-dressing with Lime and Fertilizer. — The use of only lime and super- 

 phosphate has been reasonably successful in sections where silt loam and clay 

 loam soils are found and also on lands recently cleared of timber where the soils 

 have a high content of organic matter. Since neither extensive areas of silt loam 

 and clay loam soils nor lands recently cleared of timber are found in Massachu- 

 setts, this type of treatment for permanent pastures has met with only limited 

 success here. Some of the heavier soils in Franklin and Berkshire counties do 

 give a moderate response to treatments with lime and superphosphate, but most 

 of the lighter soils both in these two counties and elsewhere in the State do not. 



The application of potash in addition to lime and superphosphate has produced 

 moderately good results on a much greater variety of soil types than has just 

 lime and superphosphate. This is to be expected since it has already been shown 

 that the potassium deficiency in many Massachusetts soils is more acute than 

 phosphorus deficiency. The response of all clovers to application of potash in 

 Massachusetts has long been observed. ^^^ 



If moisture relationships are such that a complete mineral treatment cannot 

 be relied upon to induce a good growth of natural white clover, nitrogen must 

 be added to the top-dressing mixture. Grasses must have plenty of nitrogen 

 to produce a satisfactory growth, and if a legume cannot be relied upon some 

 other source must be provided. Permanent pasture grasses are more widely 

 distributed than natural white clover in Massachusetts, with the result that 

 there is a considerable area of land which will respond to a complete fertilizer. 

 It is by no means uncommon in badly depleted pastures for a complete fertilizer 

 to actually stimulate the growth of natural white clover. Quite often nitrogen 

 alone is applied on permanent pasture in the early spring to provide early spring 

 grazing. Although this provides an economical source of early spring feed, nitro- 

 gen alone without additional use of lime and mineral fertilizers will merely hasten 

 the depletion of essential soil minerals and thereby hasten pasture deterioration. 



Detailed recommendations for the kinds and amounts of lime and fertilizer 

 materials to use, together with a description of how and where they may be ap- 

 plied, are available in several current publications. i^^ 



Fertility Improvement and Maintenance in Semi- Permanent Pastures 



The fertility problem in semi-permanent pastures is handled much the same 

 as for any tilled crop. The land is plowed, then adequately fertilized using suit- 

 able fertilizer materials including barnyard manure if available, and finally worked 



ISSMass. State Bd. Agric. 54th Annual Report (1906), p. 150. 



134international Seed Testing Association Proceedings, X (1938), 93-122. 



135wm. P. Brooks, Hatch Expt. Sta. (Mass. Agric. College). 6th .Annual Report (1894), p. 9. 



136Mass. State College Extension Leaflet 150 (1940). 



