Last update: April 11, 2012 08:06:39 AM E-mail Print

 

Hints on the Growing and Utilization of Lucerne.

D. W. McKellar and C. C. Claassens

 

WATER being the lifeblood of crop production in South Africa, growers should have a full appreciation of its economical utilization, not only with respect to yield, but also with respect to the quality of the crop produced.

 

Irrigation

The irrigation of a crop like lucerne in many cases does not receive the serious attention of our farmers. Water is frequently applied without regard to the actual requirements of the crop and the way in which those requirements are influenced by the type, fertility and depth of soil, etc. This means that in many instances our farmers are not aware of the cost of the water in relation to the yields obtained.

Lucerne yields tend to increase with an increase in the quality of irrigation water applied, up to the point of maximum production, but the higher yields are usually obtained at a disproportionate cost in water. In other words, it means that with a light irrigation lucerne will usually produce two or three times as much per unit of water used than when heavy irrigations are applied. Consequently it is often more economical to increase the area under the crop and to reduce the amount of water applied per unit of land, especially where the land available is plentiful and the water supply limited. In this case it is, of course, essential to take into consideration the cost of preparing the larger area.

 

Quality

Apart from the efficacy of light irrigations, however, the part played by water in respect of the quality of the hay produced, is not generally appreciated. The high feeding value of lucerne is an established fact, though this may be influenced materially by the care exercised during the haymaking process as well as by the stage of cutting etc. The leafiness of the hay is largely an indication of its quality and value, and this can be affected to a marked extent by the amount of water the crop receives during the growing period. Experimentally it has been revealed that lucerne grown over a period of 6 years under a range of irrigation treatments consisting of no irrigation (average rainfall 15 inches), 13 inches, 36 inches, and 96 inches per season furnished hay with a leaf content of 62.4 percent; 53.9 percent, 50.2 percent, and 45.7 percent respectively. On analysis the feeding value of this hay was reflected by a corresponding crude-protein content of 22.99 percent, 21.64 percent, 20.68 percent and 17.87 percent respectively.

The appearance of the lucerne grown with these varying quantities of water have a very misleading impression of the feeding value in that very heavy irrigations gave a luxurious growth of tall, luscious, large-leaved lucerne, while, actually, stalk development had taken place at the expense of leaf content, as the figures revealed. This is an additional reason why greater care should be exercised in the application of water to lucerne, for it affects not only the economical utilization of the water in relation to the yield obtained but also the quality of the hay produced.

 

Grazing

In areas where lucerne is cultivated extensively under the irrigation schemes, farmers find that the production of lucerne hay for sale at prevailing prices offers a very poor livelihood. The result is that irrigation farmers are devoting themselves to an increasing extent to the feeding of milk-cows and slaughter-sheep, with a view to marketing their lucerne more profitably in the form of animal products.

The general practice of lucerne farmers is, wherever possible, to allow a portion of their lucerne to be grazed, and to cut the remainder for hay, which is either sold or retailed for use as stock feed. Grazing, however, has the effect of shortening the life of the stand of lucerne and is, moreover, attended by the constant danger of hoven, which may bring about the loss of valuable animals. In the case of haymaking too, there is an element of risk: heavy loss may be occasioned by various factors. The most important of which is rain during the cutting process - something which is beyond the control of the farmer.

It is difficult to determine the extent of all these losses in terms of money, but the losses sustained in the areas along the Fish River as a result of rainfall during cutting amount to about £45 per farmer per annum. The holdings in this area average 40 morgen in size, 40 percent of which is planted to lucerne. The general practice is to allow half the lucerne to be grazed, and to utilize the remainder for haymaking. Enquiries made in this area have revealed that 30 percent of the lucerne lost on account of rain falling at the time of cutting. As a basis for this calculation, the average output was estimated at 8 tons per morgen and the price at £2 per ton.

While it is practically impossible to eliminate all losses in farming completely, much can nevertheless be done to reduce the effects of rainfall and other factors to a minimum.

Experience in general has shown that grazing limits the life as well as the yield of lucerne. At no time, for example, should a cultivated land be grazed when wet, or before the stand of lucerne is two years old. Moreover, it should not be grazed too short; horses and sheep are the most destructive animals in this respect. At the Grootfontein College of Agriculture it has been found that continuous grazing is fatal to the lucerne, white grazing during spring and autumn is almost equally injurious. During summer when there is a strong growth, grazing is less detrimental, but even then, it is advisable to graze a land rapidly, and then to give it an opportunity to grow again. Another fact, which should be borne in mind, is that no stand of lucerne should be grazed twice in succession; the growth, which comes up after the crop has been grazed, should be cut.

 

Hoven in Stock

In all areas where lucerne is grazed, the danger of hoven in cattle and sheep is well known, and most farmers are acquainted with methods for the effective treatment of this trouble. The result is that farmers must constantly be on their guard against this menace, and even then losses are suffered owing to the fact that there are practically no effective ways of preventing hoven from occurring in animals grazing on lucerne.

An effective method of feeding green lucerne to cattle without the danger of causing hoven, has been introduced along the Orange River, and is probably employed in other areas too. The green lucerne is cut and immediately stacked in a heap to sweat for 36 to 48 hours. At the end of this period considerable heat will have been generated in the heap and the- colour of the lucerne will be light brown instead of green. As a rule a quantity sufficient to supply the needs of the animals for three days is cut and carted to the cowshed. This means that the last portion is fed five days after the cutting. A considerable saving of labour is effected by the application of this three-day method. Such green sweated lucerne is very eagerly eaten by animals, and as far as is known not a single case of hoven has occurred where the lucerne has been fed in the discoloured condition. While this method of feeding does entail a considerable amount of labour, the losses arising from the feeding of hay and grazing on the land, are effectively eliminated during the period of growth of the crop.

 

Silage

Since lucerne cannot be stored and transported on a large scale in any other form, the haymaking process will continue in spite of losses resulting from rainy weather. On areas where rain is generally experienced at cutting time, it is, however, important that such losses should be reduced to a minimum. This can undoubtedly be done most effectively by ensiling the lucerne. Cases are known where lucerne has been successfully ensiled without any treatment, but since this crop does not contain sufficient sugars for conversion (in the silo) into acids for protecting the mass against decay, it is desirable to add 1½ percent molasses to the lucerne before ensiling the crop; since undiluted molasses is too viscid or sticky, it should be diluted with four parts of water. This means that 30 lb. of molasses dissolved in 12 gallons of water should be added to a ton of green lucerne.

Since it is a well-known fact that silage constitutes the cheapest form in which feed can be stored while at the same time ensuring good milk production during the lean seasons of the year, it would appear that the chief condition for success in irrigation areas where lucerne is the main crop is to ensile the lucerne.

 

Published

Farming in South Africa 16