No abstract

Salinity is one of the most damaging abiotic stresses due to climate change impacts that affect the growth and yield of crops, especially in lowland rice fields and coastal areas. This research aimed to isolate potential halotolerant plant growth-promoting rhizobacteria from different rhizo-microbiome and use them as effective bioinoculants to improve rice growth under salinity stress conditions. Bioassay using rice seedlings was performed in a randomized block design consisting of 16 treatments (control and 15 bacterial isolates) with three replications. Results revealed that isolates S3, S5, and S6 gave higher shoot height, root length, and plant dry weight compared with control (without isolates). Based on molecular characteristics, isolates S3 and S5 were identified as Pseudomonas stutzeri and Klebsiella pneumonia. These isolates were able to promote rice growth under salinity stress conditions as halotolerant plant growth-promoting rhizobacteria. These three potent isolates were found to produce indole-3-acetic acid and nitrogenase.

The spore-forming Bacillus and cysts forming Azotobacter are Plant Growth Promoting Rhizobacteria which has been used as biofertilizer in sustainable agriculture since they tolerant to dried soil. Drought resistant microbes will be useful to coat urea in order to reduce the lost of nitrogen. The objectives of this preliminary study were to study the effect of molasse based liquid media on the population of Bacillus spore and Azotobacter vegetative cell and to determine the composition of four bacterial species in liquid formula. In the first experiment The Bacillus subtilis, B. megaterium, A. chroococcum and A. vinelandii were grown separately in 1% cane molasses enriched with 0.1% NH4Cl. As control treatment, The Bacillus and Azotobacter were grown in Nutrient Broth and Ashby’s mannitol broth respectively. In the second experiment, different composition of said Bacillus and Azotobacter were grown in molasses based liquid media prior to count the spore and vegetative cell. The results showed that molasses-based media supported bacterial growth and initial ratio 1:1:1:1 of liquid inoculant was effective to increase bacterial growth. This experiment suggested that the use of organic based media was useful practice of liquid biofertilizer formulation for granule urea coating.

No abstract

In Indonesia, Inceptisols is the largest soil order on which intensive agriculture is done. The fertility of this soil order is low, so that it is necessary to improve the soil fertility by using biofertilizers and organic matter. The objectives of this experiment were to determine the effect of a biofertilizer that contains microbe Azotobacter sp., Vermicompost and N, P, K Fertilizer on N content, the population of Azotobacter sp., and the yield of the Edamame soybeans at Inceptisols Jatinangor. A Field experiment was conducted by using Randomized Blocked Design consisted of 10 treatments and three replication. The combinations of these treatments consisted of: control (no treatment), the dose recommendation Urea 100 kg ha-1 + SP36 150 kg ha-1 + KCl 125 kg ha-1, 5 ton ha-1 vermicompost + ½ recommendation ha-1 N, P, K, 5 ton ha-1 vermicompost + 1 recommendation ha-1 N, P, K, 5 ton ha-1 vermicompost + 1½ recommendation ha-1 N, P, K, 10 ton ha-1 vermicompost + ½ recommendation ha-1 N, P, K, 10 ton ha-1 vermicompost + 1 recommendation ha-1 N, P, K, 10 ton ha-1 vermicompost + 1½ recommendation ha-1 N, P, K, 5 ton ha-1 vermicompost +  ½ recommendation ha-1 N, P, K + liquid biofertilizers 5 L ha-1, 10 ton ha-1 Vermicompost + ½ recommendation ha-1 N, P, K + liquid biofertilizers 5 L ha-1.  The experimental results showed that the combined treatment of liquid biofertilizer, Vermicompost and N, P, K fertilizer enhanced the population of Azotobacter sp. and weight of soybean but did not significantly influence N uptake.