Trace metals distribution and uptake in soil and rice grown on a 3-year vermicompost amended soil

This study was designed to investigate the influence of vermicompost (VC) on trace metals distribution and uptake in soil and rice plant in research field as split plot arrangement based on randomized complete block design with three replications in 2008. Main-plot was VC and chemical fertilizer (CF) that were added to soil in 6 levels (20 and 40 ton/ha VC, 20 and 40 ton/ha VC + 1/2 CF, CF and control). Application years considered as sub-plot comprised 1, 2 and 3 years. The results indicated thatfertilizers and application periods treatments influenced micronutrients in soil and rice. Available copper (Cu) had no significant difference under different treatments. The highest available iron (Fe) was found in the 40 ton treatment group. During the 3 years, application of 20 ton and enriched 40 ton gave the most available zinc (Zn) and manganese (Mn). In VC and enriched VC, treatments happened to give the highest Zn uptake by rice. Under the 3 years, application of 40 ton/ha VC, the highest Fe (91.19 ppm) and Cu (13.66 ppm) concentration was seen in flag leaf, while Fe (31.35 ppm) and Mn (27.56 ppm) was seen in grain. With the application of enriched 20 ton VC, the maximum uptake of Mn by flag leaf and Cu by grain was obtained

Nutrient use efficiency and nutrient uptake promoting of rice by potassium solubilizing bacteria (KSB)

The current study was carried out in both pot and field conditions to investigate the effects of three KSB strains of Pantoea agglomerans, Rahnella aquatilis and Pseudomonas orientalis on nitrogen (N), phosphorous (P) and potassium (K) uptake, nutrient use efficiency parameters and nutrients remobilization in rice (Oryza sativa L. cv. Pajohesh). The experiments included 15 treatments of KSB inoculations, commercial K biofertilizer and K chemical fertilizer. The results showed that the inoculums of all three KSB strains increased the K, N and P uptake by grain and straw, especially when applied in combination with ½ K chemical fertilizer (47.5 Kg/ha) as compared to the control treatment. The highest value of available K in the soil obtained from NPK chemical fertilizer equal to 140.1 and 134.6 mg K per kg of soil in the pot and field experiments, respectively, which were significantly higher than KSB inoculations treatments. Bacterial inoculums coupled with ½ K chemical fertilizer also enhanced the nutrient use efficiency (including agronomic efficiency (AE), apparent recovery efficiency (ARE), physiological efficiency (PE), agro-physiological efficiency (APE), internal utilization efficiency (UE), partial factor productivity (PFP), partial nutrient balance (PNB)) and nutrient remobilization. The results indicated that the bioinoculation with these KSB strains isolated from soil paddy could be considered as an effective way to increase potassium, nitrogen and phosphorus uptake by rice plant and enhance their use efficiency and remobilization to grains in the flooding irrigation conditions

The Growth Analysis of Corn (Zea mays L. cv. SC 604) With Different Fertilizers Application

To investigate the responses growth indices of corn (Zea mays L. cv. SC 604) to using plant growth promoting rhizobacteria (PGPR) and phosphate solubilizing microorganisms (PSM) and rhizobacteria, a field experiment was conducted during 2008. The study was arranged in split plot experiment based on randomized complete block design with three replications. Three levels of manures, consisted of 20 Mg.ha-1 farmyard manure, 15 Mg.ha-1 green manure and check or without any manures assigned to main plots and eight levels of fertilizer combinations (consisted of 1-NPK or recommended fertilizer application; 2-NPK+PSM+PGPR; 3-NP50%K+PSM +PGPR; 4-N50%PK+PSM+ PGPR; 5-N50%P50%K+PSM+ PGPR; 6-PK+PGPR; 7-NK+PSM and 8-PSM+ PGPR) to sub plots. Results showed that the maximum dry matter (13/2 g.m-2), leaf area index (3/8) and crop growth rate (34/5 g.m-2.day-1) were, produced by using both farmyard manure and application of NPK plus biofertilizers. Application of green manure and biofertilizer significantly increased dry matter by 11% compared to control. Meanwhile, farmyard manure and green manure application markedly increased the leaf area index by 17 and 10%, respectively. NPK treatment in farmyard manure plots and inoculation of PGPR and PSM significantly increased crop growth rate in corn plants compared to green manure and control plots. However, inoculation of biofertilizer and reducing P application by 50% did not significant influence growth indices such as total dry matter accumulation, leaf area index, and crop growth rate significantly. In conclusion, it seems that biofertilizers could be recommended as an effective option to reduce phosphate chemical fertilizers, improve the growth indices of corn plants, which ultimately result in grain yield increase

The Effect of Different Levels of Nitrogen Fertilizer on Yield and Agronomic Characteristics of Basil (Ocimum basilicum L.) Intercropped with Cowpea (Vigna unguiculata L.) and Affected by Weed Competition

In order to study the intercropping of basil (Ocimum basiilicum L.) and cowpea (Vigna unguiculata  L.) under different levels of nitrogen supply and weed competition conditions, a field experiment was carried out in split-split plot arrangement based on a randomized complete block design with three replications during 2010 and 2011 at Sari Agricultural Science and Natural Resources University. Experimental factors included weed treatment (weed free and weed infested), three levels of nitrogen fertilizer (0, 50 and 100 kg ha-1), and different planting ratios (monoculture of cowpea and basil, additive planting ratio 25, 50 and 75% basil). In weed control conditions, the maximum yield of cowpea (684 kg ha-1) and dry matter yield of basil (420 kg ha-1) were belonged to 20, 50 percent of basil ratio and 50 and100 kg ha-1 nitrogen fertilizers, respectively. The highest amount of essence yield in weed free and weed infested were 69.24 and 70.40 percent as compared to the basil monocropping which belonged to 50 and 25 percent of additive basil intercropping with 100 kg ha-1 nitrogen application, respectively. Also, the dry weight of shoot and oil yield in monoculture treatments were significantly higher than intercropping. The leaf percent and the ratio of leaf and flower to stem in basil plant were significantly lower in monocropping than intercropping. In weed infested conditions, the highest percentage of stem (62.18) and basil dry yield (160 kg ha-1) were recorded in 25 percent of basil ratio and 100 kg ha-1 of nitrogen application. Also, the highest system productivity index (1517) and land equivalent ratio (LER=1.31) were belonged to 50 percent of basil ratio and 50 kg ha-1of nitrogen fertilizer in weed free conditions which shows that intercropping is more efficient than monocropping

The Effect of Trichoderma harzianum and Cadmium on Tolerance Index and Yield of Barley (Hordeum vulgare L.)

To investigate the effect of Trichoderma harzianum, as a bioabsorbant to ameliorate the harmful effects of cadmium (Cd) on growth and yield of barley (Hordeum vulgare L. variety ‘Sahra’), a factorial pot experiment based on completely randomized design with three replicates was conducted. Trichoderma harzianum withtwo levels (with and without inoculation) and cadmium nitrate with four levels (0, 50, 100 and 150 mg.L-1) were the treatments. Results of ANOVA revealed that there was a significant interaction between Trichoderma and cadmium nitrate in terms of biological yield, straw yield, harvest index, spike number per plant and seed number per spike. Mean comparisons showed that Trichoderma inoculation at all Cd levels significantly improved both biological and straw yields. Trichoderma at 50 and 100 mg.L-1 of Cd also increased the spike number per plant (up to 120 and 66%, respectively) significantly. Increasing Cd levels decreased seed yield (19%), 1000 seed weight (18%), partitioning coefficient (57%) and tolerance index (23%) significantly. Inoculation of Trichoderma into growth medium had a significant effect on seed yield and tolerance index (up to 17 and 22%, respectively). In conclusion, Trichoderma harzianum inoculation at lower concentrations of Cd (50 and 100 mg.L-1) could be effective to improve growth parameters of barley plant