Assignment 7: Revised Wikipedia Assignment (12/13/2015) - 481 words

Although Tephrosia vogelii is not consumed directly, it can be used to increase the yield of various crops.[1] For example, leaf extracts of Tephrosia vogelii are used as chemical pesticides. Crops that have had this extract applied show significant decreases in insect and other pest activity. Therefore, crops can grow in areas that they could not before, if they are grown along side Tephrosia vogelii. In fact, studies have shown a 46.2-52.2% decrease in grain damage. Grain damage was measured by the amount of kernels that were destroyed and also by the net weight loss of the crop. This number varies based on method of storage, type of insect measured, and type of stored grain. In one particular study, the extract killed 40% of the attacking insects after a 21 day period. This decrease is about what would be expected from most chemical pesticides.[2]

However, insecticide is not its only use. Tephrosia vogelii can also increase various nutrients in the soil and is often used in intercropping. Studies have shown a 30% increase in soil nutrients, and as a result, a 23-26% greater crop yield.[3] Tephrosia treatments increased organic carbon and mineral nitrogen in the soil. The experiment that discovered this used pots with various concentration of Tephrosia vogelii to be grown along with corn. The pots that contained Tephrosia showed a large increase in nitrogen and carbon. To determine this, researchers used weeds and insects to measure nitrogen and potassium content of the soil, respectively.[4] Therefore, a well designed intercropping system could dramatically increase crop production in arid land. Normally, if crops are grown together, there is less yield then if they were grown alone. This shows that Tephrosia vogelii has a synergistic effect with multiple crops including coffee and corn. Increased nutrients are yet another way Tephrosia vogelii can improve the yield of other crops. Tephrosia might not grow well alone, but if it is grown along with another crop, it can grow up to 6 times more than it would alone.[5] Its poor growth is often due to the high acidity of the soil, as well as low calcium, low sodium, and low potassium.

Although an increase in organic carbon is important, the main function of Tephrosia vogelii is to increase nitrogen content in the soil. This increase can be measured using organisms that feed off the nitrogen. However, as this is not a direct measurement, the crop yield might be over or underestimated. Tephrosia vogelii can be used in any environment, but it is best used in an arid environment such as southern and eastern Africa, where crops are extremely difficult to grow alone.[5] Using it, farmers can maximize the amount of crop yield by increasing soil fertility, and removing insects and other pests. If this species is developed further, it might be able to provide an even greater synergistic effect and crop yield in these arid environments.

  1. ^ Kuntashula E, Sileshi G, Manfongoya PL, Banda J (2006). Farmer participatory evaluation for the potential for organic vegetable production in the wetlands of Zambia. Outlook on Agriculture 35(4): 299-305.
  2. ^ Chebet F, Deng AL, Ogendo JO, Kamau AW, Bett PK (2013). “Bioactivity of Selected Plant Powders against Prostephanus truncates (Coleoptera: Bostrichidae) in Stored Maize Grains.” Plant Protection Science 49(1): 34-43.
  3. ^ Bucagu C, Vanlauwe B, Giller KE (2013). “Managing Tephrosia mulch and fertilizer to enhance coffee productivity on smallholder farms in the Eastern African Highlands.” European Journal of Agronomy 48: 19-29.
  4. ^ Ngegba MS, Mugasha AG, Chamshama SAO, Kimaro AA (2007). “Tephrosia biomass yield and soil fertility in one season relay intercropping with maize in semiarid gairo, Tanzania.” Discovery and Innovation 19: 24-35.
  5. ^ a b Sileshi G, Mafongoya PL (2003). “Effect of rotational fallows on abundance of soil insects and weeds in maize crops in eastern Zambia.” Applied Soil Ecology 23(3): 211-222.