Agronomy Of Pasture And Fodder Crops In Kenya

The agronomy of pasture and fodder crops in Kenya is essential for the country’s livestock industry, which plays a vital role in the agricultural sector and the overall economy. Adequate pasture and fodder production are critical for supporting the nutritional needs of livestock, improving animal health, and enhancing milk productivity. Here is an overview of the agronomy of pasture and fodder crops in Kenya:

The most important constraints to improve livestock production, in particular dairy production, are related to animal nutrition. When (cross-bred) dairy cows are kept on small-scale farms, planting improved pastures and fodder crops is essential. To obtain increased milk yields the animals should be provided with supplementary feeds next to the grazing of natural grasses. Improved pastures, especially when legumes are included, can produce large quantities of high quality feed for the dairy animals at a low cost.

Several possibilities are available to the farmer to improve the ration of his animals. These include:

1. planting of improved pastures for grazing;
2. planting of fodder crops for supplementary feeding during the dry season;
3. cutting natural grass in the veldt or improved pasture for making hay;
4. inter-cropping legumes in maize and/or grass to improve the nutritional quality and the utilization of the

Grasses should not be utilized in a too late stage of maturity. The leave- stem ratio determines the digestibility and thus the feeding value. Young grasses are green and leafy and very tasteful to the animals. Once grasses grow older, they develop a thicker stem and become more fibrous. In this way they loose much of their feeding value. In particular the protein content is reduced. Therefore grasses should be utilized before they start blooming and produce seeds. When one waits too long, it is true that one will harvest a bigger quantity of grass, but the quality will be reduced with about 20 %. Therefore it is advisable in case pastures are grazed, to make paddocks over which the animals can be rotated. Then you are able to provide your animals continuously with young, fresh grass.

Legumes are able to fix Nitrogen from the air and to convert this into proteins. For that reason legumes are richer in proteins than grasses and other fodder crops. The plants contain relatively more leaves and less stem than grasses. In the leaves we find about 80 % of the protein. Therefore legumes should be cut when about half the crop is in bloom.

In that stage we still have sufficient leaves on the plant and a not too fibrous stem. When legumes grow too old they produce some poisonous substances. If fed in too big quantities these can cause skin problems and bloat. To prevent bloat in the animals pure stands of legumes should never be used for grazing. Especially not in early morning when the plants are wet due to dawn. After cutting, the legumes should always be left to wilt in the sun. Only when the plants are sundried, they can be fed to the animals.

The following are a few examples of grasses and legumes that are recommended as improved pasture and fodder crops.

Grasses

 Rhodes Grass

Rhodes grass is tolerant to a wide range of soils, from light sandy to clays. But it will not withstand water logging. It provides excellent first season grazing and hay. But yields in subsequent seasons decline if it is not fertilized and weeded. Replanting is necessary after about 3 to 5  years.

Establishment:

The grass is established from seed. It can be sown in rows of 0.5 to 1.0 m apart or be broadcasted at a rate of 3 to 7 kg seeds per hectare. Fresh seed is best stored for a period of 6 months before planting.

The seed should be sawn at most 1 cm deep. The seedbed should be lightly rolled if it is drilled and harrowed or swept over (using branches) lightly if it is broadcasted. In this way the seeds are not pushed too deep into the soil. Sowing should not take place until the rains are well established.

Fertilizer:

To increase the growth of the grass and to improve its quality, the crop has to be supported by either use of artificial fertilizers or cattle manure and/or compost. Since the cost of fertilizer in Zambia is prohibitive, smallholder dairy farmers are advised to apply as much cattle manure as possible into their field. This should be applied before planting and in the dry season, once the crop has established well. A topdressing of D compound at the rate of 100 kg per hectare is recommended.

Management:

New stands of Rhodes grass should be allowed to set seed before cutting, especially if the stand was poorly established. Manual weeding can be carried out in the month of December/January. Peak grass production is usually obtained in the first two seasons. Thereafter it is recommended to allow the stand to flower, set and shed seed before harvest. After 3 to 5 years it is best to plough and replant.

Buffel Grass (Fox Tail Grass)

Buffel grass is tolerant to a wide range of soil conditions with the exception of water-logging. Buffel grass does best on light soils in medium and low rainfall areas. It is more drought and fire tolerant than Rhodes grass. Also it remains green for longer periods than Rhodes.

It is therefore more suitable as a permanent pasture.

Establishment:

The same procedure is followed as described above for Rhodes grass. Only more seed is used at a rate of 6 – 8 kg per ha. The lower seed rate of 6 kg is used for planting the seed and a higher rate when broadcasting. Fresh seed usually will not germinate during 9 to 12 months after harvesting (due to dormancy) and so should not be used.

Fertilizer:

As for Rhodes grass.

Management:

Buffel grass persists well and hence may not need replanting for several years. It is tolerant to fire and so controlled burning can be used to clear the old growth and weeds at the end of the dry season.

Buffel grass has certain features that make it easier to establish, manage and maintain than Rhodes grass. Especially under Zambian soil and climatic conditions. However, the fact that Rhodes grass is more palatable and nutritious and that the seed is more readily available, makes this often the better choice for the smallholder dairy farmer.

Napier / Bana grass

Since Bana grass is a variety of Napier grass, both names are used simultaneously. It is a highly recommended fodder to supplement the feeding of dairy animals. Napier grass is high yielding and as it is reasonably drought resistant, it remains green into the dry season. Therefore it can be used very well in the formation of a fodderbank, which can be used during the dry season. Napier grass should not be grazed by the animals, but is very suitable for cutting. If properly managed the feeding value is good and if fed at an early stage the palatability is very good. Napier grass prefers well drained soils, but can be grown on almost any soil.

Establishment:

It is advisable to plant Napier grass near to the night paddock of the animals. That makes it easy to carry the cut grass to the animals, but also to return the manure from the paddock to the Napier field. The grass should be planted in rows, with a spacing of 90 cm between the

rows and 60 cm in the row. It is the easiest to plant cane cuttings, similar to sugar cane. These can be obtained from overgrown Napier grass. Use the middle part of the stem and cut this into pieces with 3 – 4 nodes each. These cuttings are pushed into the soil under an angle of 45 º so that at least 2 nodes are covered by the soil. Also rootsplits can be used. As handling these splits is much more laborious, this procedure remains usually restricted to fill gaps in already established fields.

Fertilizer

When cutting the Napier grass large quantities of nutrients are removed from the soil. These have to be replaced. Therefore it is important to return as much as possible manure close to the plants. In addition artificial fertilizer should be applied at a rate of 10 bags NPK per ha per year. To stimulate the growth of Napier grass well into the dry season, half of this amount can be applied towards the end of the rainy season.

Management

If properly managed, Napier grass remains productive for 10 – 15 years. The quality of the grass is reflected by a dark green colour. Cutting is done best when the grass is 60 – 90 cm tall. Do not let it overgrow. It becomes more bulky then, but the quality is reduced seriously. If you have excess Napier during a certain period, it is better to cut the grass in the right stage and make silage out of it, than leaving it in the field to overgrow. After each cutting, the grass should be weeded and manure can be applied.

Legumes

 Velvet bean

Velvet bean is a vine. Without support it will spread over the ground, producing large quantities of vegetative material. This is a desirable feature. It is mostly cut as a forage and occasionally for its seed. It is also recommended as a good cover crop for farmers who practise conservation farming. If grown for hay or silage the crop should be cut when the first pods reach their full size but are still green.

Establishment:

Velvet bean is more drought tolerant than cowpea and requires a long warm growing season. It tends to suffer from root rot in high rainfall areas and does not tolerate water logging. Planting should be done at a rate of: 40 – 50 kg seeds per ha in rows of 0.5 to 1 m apart, if the crop is grown for it’s leafy material as a fodder. The depth of the seeds should not exceed 2 to 3 cm 15 – 20 kg seeds per ha if it is intercropped with maize or sorghum as a mixture to make silage.

Management:

Velvet bean requires regular weeding in the first weeks as it grows slowly initially. Later on it effectively smothers all weed competition. Velvet bean makes an excellent silage if intercropped with cereal crops, like maize, sorghum, pearl millet, etc. When feeding fresh to livestock it should be combined with hay or a cereal fodder in a ration of 1 part velvet bean to 3 parts hay, green maize or sorghum. The grinded seeds can be used up to 15 – 20 % in a dairy meal mixture as a source of protein. However, it should only be given to cows, oxen or bulls and not to young stock.

Cowpea

Cowpea is a spreading annual legume that can be used as a fodder for livestock to provide green fodder, hay, silage or grain as a concentrate. It is drought tolerant. Green pods and dry beans are also used for human consumption. It is a triple purpose crop since it serves as a fodder, as a human food and it increases the fertility of the soil.

Establishment:

Cowpea should be planted in soil that is well-drained and free of weeds at a seed rate of about 15 – 20 kg per ha. It is best to keep the crop free from weeds for the first four weeks after which it naturally smothers weeds.

Management:

Cowpea is susceptible to attack by fungi. Apart from spraying fungicides, the best way to prevent this is to practise crop rotation. Blister beetles might eat the flowers. If these beetles are found, destroy them by hand or use a suitable insecticide.

As a feed for livestock, the green leaves can be plucked regularly or the whole crop can be harvested when the pods are green. The complete plant can be incorporated in silage or be dried as hay. The seeds can be dried and ground and fed as a meal. In addition pods can be fed whole, either fresh or dried. Cow pea is an excellent fodder crop for smallholder dairy farmers.

Red Sun-hemp

Sun-hemp is a tall, upright, slender annual legume. It is predominantly used for green manure (due to its rapid growth), but also used for silage, hay or fibre. It will grow on practically any soil. It improves those which are highly infertile and it is generally free from most diseases and insect pests. In addition, it is not very sensitive to weeds. Exclusive feeding of sun-hemp to dairy animals is not recommended. It must be mixed with hay, silage, green maize or green sorghum. Animals may not like the taste in the beginning but after some time they become used to it.

Establishment:

Seed should be drilled in a smooth seedbed that has been ploughed and harrowed. Planting should be done at a rate of 10 – 15 kg per ha in rows of 0.5 to 1 m apart. Planting is carried out soon after the rains have started.

If being grown for hay or silage, it is best to cut when the crop starts to flower. If rainfall is good 2 cuttings can be taken in a year. Black sun-hemp can also be used, but is more fibrous and woody than red sun-hemp. The seed rate for black sun-hemp is about 25 – 30 kg per ha.

Dolichos Lablab

Dolichos lablab is an excellent leguminous cover crop. Lablab will grow on a wide range of soils but does not withstand waterlogging. It shows an excellent growth in the rainy season and is tolerant to drought. So it does well even in low rainfall areas. It can be grazed or used for hay or silage. The whole seed and green pods can be fed to stock as a protein supplement and these can be used as a relish in human consumption. It is a perennial plant and it sprouts during the dry season. Therefore it can also be used as a green fodder during the dry season.

Establishment:

The seed should be sown in a smooth seedbed that has been ploughed and harrowed. The seed rates are similar to those of velvet beans.

Fertilizer:

The crop will benefit from application of manure, which has to be ploughed in before planting.

Management:

It can both be grazed (it is more tolerant than cowpea to grazing) and becut and carried. It is best to use it fresh, as it dies slowly and tends to shed most leaves in the process.

Pod borers and blister beetles can attack flowers and young pods. These should be controlled by spraying.

The first cuttings are available 6 – 8 weeks after emergence and then again after 4 to 6 weeks. It is best not to cut lower than 15 cm from the ground. Like cow pea, it is also a triple purpose legume.