Siratro

Macroptilium atropurpureum

Macroptilium atropurpureum, commonly known as Siratro or purple bushbean, is a warm-season perennial legume belonging to the Fabaceae family. Native to tropical and subtropical regions of the Americas, Siratro has been widely used as a forage crop and cover crop due to its nitrogen-fixing abilities and soil improvement characteristics.

Description:

  • Growth Form: Siratro is a trailing or climbing legume with a prostrate growth habit. It can form dense mats of vegetation on the ground or climb on surrounding vegetation for support.

  • Leaves: The leaves are compound, consisting of three leaflets. Leaflets are elliptical to ovate, with serrated edges. The upper surface of the leaves is usually dark green, while the lower surface may have a purplish tint.

  • Flowers: The flowers are typically arranged in clusters and are attractive shades of purple or pink. They are bilaterally symmetrical and have a characteristic pea-like appearance.

  • Seeds: The seeds are produced in pods, each containing several small, oblong seeds. The seeds are typically dark in color.

Identification:

Identifying Macroptilium atropurpureum involves recognizing its key features:

  1. Compound Leaves: Look for leaves with three elliptical to ovate leaflets.
  2. Trailing or Climbing Habit: Observe its prostrate growth habit, forming dense mats, or climbing on surrounding vegetation.
  3. Distinctive Flowers: The flowers are clustered and have a distinct pea-like shape, typically in shades of purple or pink.

Ecological Significance:

Siratro is valued for its role as a forage crop, cover crop, and green manure. It is often used in tropical and subtropical regions to improve soil fertility through nitrogen fixation. Additionally, it provides nutritious forage for livestock.

Cultural Uses:

  1. Forage: Siratro is commonly used as a forage crop for livestock, providing a good source of nutrition.
  2. Cover Crop: Due to its ability to fix nitrogen and protect soil from erosion, Siratro is used as a cover crop in agriculture.
  3. Green Manure: When plowed into the soil, Siratro adds organic matter and nitrogen, improving soil fertility.

Management:

  1. Establishment: Siratro is typically established through seed sowing. It is important to ensure proper seedbed preparation for successful establishment.
  2. Fertilization: While Siratro is known for fixing atmospheric nitrogen, providing phosphorus can enhance its growth in low-phosphorus soils.
  3. Grazing and Harvesting: Proper management of grazing or harvesting is crucial to maintain the persistence and productivity of Siratro stands.