benefits of incorporating Azolla in rice cultivation

Other benefits of incorporating Azolla in rice cultivation

As well as its nitrogen biofertilization, Azolla provides a variety of benefits for rice production and grows in a way that is complementary to rice cultivation:

[1] The thick Azolla mat in rice fields suppresses weeds.

[2] Since Azolla floats at the water surface, it does compete with rice for light and space.

[3] In most climates, Azolla grows best under a partial shade of vegetation which is provided by the rice canopy during early and intermediate stages of growth

[4] When the rice approaches maturity, Azolla begins to die and decompose due to low light intensities under the canopy and a depletion of nutrients, thus releasing its nutrients into the water.

[5] Because Azolla decomposes rapidly, its nitrogen, phosphorus and other nutrients are rapidly released into the water and made available for uptake by rice during grain development.

[6] Azolla has a greater ability than rice to accumulate potassium in its tissues in low-potassium environments, providing rice with potassium after Azolla’s decomposition

[7] In contrast with chemical nitrogenous fertilizers, Azolla has various positive long-term effects, including the improvement of soil fertility by increasing total nitrogen, organic carbon, plus phosphorus, potassium, other nutrients and organic matter.

[8] If chemical nitrogenous fertilizers are applied, the presence of an Azolla mat reduces ammonia volatilization that would normally occur.

[9] When grown in a rice field, Azolla reduces the ammonia volatilization that occurs following the application of inorganic nitrogen fertilizers by 20% to 50%. This is due to the fact that the Azolla cover reduces light penetration into the floodwater, thus hindering the rise of pH which normally stimulates ammonia volatilization in an Azolla-free rice field (Watanabe & Liu, 1992).