The distribution of nitrogenase activity in the rice-soil system and the possible contribution of... more The distribution of nitrogenase activity in the rice-soil system and the possible contribution of epiphytic cyanobacteria on rice plants and other macrophytes to this activity were studied in two locations in the rice fields of Valencia, Spain, in two consecutive crop seasons. The largest proportion of photodependent N 2 fixation was associated with the macrophyte Chara vulgaris in both years and at both locations. The nitrogen fixation rate associated with Chara always represented more than 45% of the global nitrogenase activity measured in the rice field. The estimated average N 2 fixation rate associated with Chara was 27.53 kg of N ha −1 crop −1 . The mean estimated N 2 fixation rates for the other parts of the system for all sampling periods were as follows: soil, 4.07 kg of N ha −1 crop −1 ; submerged parts of rice plants, 3.93 kg of N ha −1 crop −1 ; and roots, 0.28 kg of N ha −1 crop −1 . Micrographic studies revealed the presence of epiphytic cyanobacteria on the surface of...
The distribution of nitrogenase activity in the rice-soil system and the possible contribution of... more The distribution of nitrogenase activity in the rice-soil system and the possible contribution of epiphytic cyanobacteria on rice plants and other macrophytes to this activity were studied in two locations in the rice fields of Valencia, Spain, in two consecutive crop seasons. The largest proportion of photodependent N 2 fixation was associated with the macrophyte Chara vulgaris in both years and at both locations. The nitrogen fixation rate associated with Chara always represented more than 45% of the global nitrogenase activity measured in the rice field. The estimated average N 2 fixation rate associated with Chara was 27.53 kg of N ha −1 crop −1 . The mean estimated N 2 fixation rates for the other parts of the system for all sampling periods were as follows: soil, 4.07 kg of N ha −1 crop −1 ; submerged parts of rice plants, 3.93 kg of N ha −1 crop −1 ; and roots, 0.28 kg of N ha −1 crop −1 . Micrographic studies revealed the presence of epiphytic cyanobacteria on the surface of...
Uploads
Papers by J. Aburto