Nutrition
Medicago sativa is an autotrophic organism. This means it produces its own sugars through a process called photosynthesis. In photosynthesis, the plant uses energy from the sun to make simple sugars which are then used in cellular respiration to create the usable energy called ATP. Water and sunlight are a must for photosynthesis to occur. Another important feature of the plant are the stomatas. The stomatas allow oxygen to exit and carbon dioxide to enter. When not in use, a stomata will close to prevent dessication. Alfalfa receives nutrients and water from the soil via their roots. Alfalfa needs potassium, phosphorus and of course nitrogen to grow. Nitrogen is a limiting nutrient in many plants. Alfalfa solves this problem by creating a mutualistic relationship with nitrogen fixing bacteria. To receive other nutrients, farmers will spray manure on fields in the winter time. It also needs a neutral to slightly alkaline soil to grow. (See habitat and geography for more information) To solve the dilemma of too much acid in the soil, farmers spread lime over fields in winter to help neutralize the soil.