Assessing the Function of Biological Soil Crusts on Soil Fertility (Case Study: Kiamaky Wildlife Refuge,East Azerbaijan,Iran)

Eurasian Soil Science - Biological soil crusts (BSCs), are common on soil surface in arid and semiarid regions. They consist of cyanobacteria, algae, fungi, lichens and bryophytes associated with...     

Early differentiation in biomass production and carbon sequestration of white poplar and its two hybrids in Central Iran

We assessed the potential of white poplar(Populus alba L.) and its inter-sectional hybridization with euphrates poplar(P. euphratica Oliv.) for carbon storage and sequestration in central Iran. Trials were established at planting density of 2,500 trees per hectare in block randomized design with three replicates. After 6 years, we measured the above-ground biomass of tree components(trunk, branch, bark, twig and leaf), and assessed soil carbon at three depths. P. alba 9 euphratica plantation stored significantly more carbon(22.3 t ha-1) than P. alba(16.7 t ha-1) and P. euphratica 9 alba(13.1 t ha-1).Most of the carbon was accumulated in the above-ground biomass(61.1 % in P. alba, 72.4 % in P. alba 9 euphratica and 56.0 % in P. euphratica 9 alba). There was no significant difference in soil carbon storage. Also, biomass allocation was different between white poplar P. alba and its inter-sectional hybridization. Therefore, there was a yield difference due to genomic imprinting, which increased the possibility that paternally and maternally inherited wood production alleles would be differentially expressed in the new crossing.     

Effect of salinity on growth and yield of Desi and Kabuli chickpea cultivars

To evaluate the effects of different level of Na salinity (0, 3, 6 and 9 dS m(-1)) on growth, yield and yield component of Kabuli (Hashem and Jam) and Desi (Kaka and Pirooz) chickpea cultivars a factorial experiment based on randomized complete block design with four replications was carried out in Research Greenhouse of Mokrian Agricultural Extension Center near Mahabad, Iran at 2006. Seeds of four chickpea cultivars were grown under 0, 3, 6 and 9 dS m(-1) levels of salinity until maturity. Salinity reduced the plant growth, flower, pod and seed number and seed weight. As increase in salinity, the undesirable effect of Na+ was more pronounced and reached the highest value at 9 dS m(-1) in all cultivars. Four chickpea cultivar have different responses to salinity and the Kabuli cultivars seemed to have a greater capacity for salt tolerance compared to Desi cultivars. Hahshem cultivar has the highest salinity tolerance among all cultivars.     

Carbon storage in biomass,litter, and soil of different native and introduced fast-growing tree plantations in the South Caspian Sea

Replantation of degraded forest using rapidgrowth trees can play a significant role in global carbon budget by storing large quantities of carbon in live biomass,forest floor,and soil organic matter.We assessed the potential of 20-year old stands of three rapid-growth tree species,including Alnus subcordata,Populus deltoides and Taxodium distichum,for carbon(C) storage at ecosystem level.In September 2013,48 replicate plots(16 m × 16 m) in 8 stands of three plantations were established.36 trees were felled down and fresh biomass of different components was weighed in the field.Biomass equations were fitted using data based on the 36 felled trees.The biomass of understory vegetation and litter were measured by harvesting all the components.The C fraction of understory,litter,and soil were measured.The ecosystem C storage was as follows: A.subcordata(626.5 Mg ha~(-1)) [ P.deltoides(542.9Mg ha~(-1)) [ T.distichum(486.8 Mg ha~(-1))(P \ 0.001),of which78.1–87.4% was in the soil.P.deltoides plantation reached the highest tree biomass(206.6 Mg ha~(-1)),followed by A.subcordata(134.5 Mg ha~(-1)) and T.distichum(123.3 Mg ha~(-1)).The highest soil C was stored in theplantation of A.subcordata(555.5 Mg ha~(-1)).The C storage and sequestration of the plantations after 20 years were considerable(25–30 Mg ha~(-1) year~(-1)) and broadleaves species had higher potential.Native species had a higher soil C storage while the potential of introduced species for live biomass production was higher.     

Combining the phosphate solubilizing microorganisms with biochar types in order to improve safflower yield and soil enzyme activity

ABSTRACT

Soil amendment with biochar could increase soil microbial activity and biomass. This study contributes to an understanding of the synergistic effects of biochar and phosphate solubilizing microorganisms on safflower yield and soil microbial activity enhancement. In the split plot experiments that repeated in two years, the main factor was biochar types included cow manure, wheat straw, wood biochar and control. The sub factors were phosphate solubilizing microorganisms included the mycorrhizal fungi (Glomus etunicatum and G. mosseae), Bacillus lentus, Pseudomonas fluorescence and control. The highest levels of dehydrogenase, urease activity and microbial biomass carbon were obtained from the cow manure biochar. The maximum activity of acid phosphatase was in the plots inoculated by P. fluorescence in all treatments, whether using or not using biochar. The grain yield of plants inoculated with B. lentus and P. fluorescence was in the same statistical group. The highest grain yield equal to 1527 kg/ha was obtained when using cow manure biochar. According to the results, the application of cow manure biochar and phosphate solubilizing microorganisms, especially mycorrhiza species, can be recommended for improving soil biological traits and safflower yield traits.     

Effect of Sodium Nitroprusside on Physiological Traits and Grain Yield of Oilseed Rape (Brassica napus L.) Under Different Irrigation Regimes

Drought stress is the main factor limiting the growth and crop yield in most regions; thus, reducing the effects of drought stress is a research priority worldwide. The aim of this experiment was to evaluate the effect of sodium nitroprusside (SNP) on physiological traits and grain yield of oilseed rape under drought stress. Two field experiments with three irrigation levels (I1: full irrigation (control), I2: irrigation cut-off at the beginning of pod development, and I3: irrigation cut-off at the beginning of grain filling) and SNP foliar applications with four levels (0, 100, 200 and 300?μM) were conducted during the 2015–2017 growing seasons. The results indicated that applying 200 and 300?μM of SNP significantly increased antioxidant enzymes, total chlorophyll, and proline at all levels of drought stress in comparison with applying zero and 100?μM of SNP. Moreover, applying SNP increased grain yield via improving the biochemical traits of the plant under stress and non-stress conditions. Comparison results of the average test of two years showed that the application of 200 and 300?μM SNP increased grain yield to 11.2 and 15.1% in control conditions, 33.6 and 36.7% in I2 and 20.9 and 40.6% in I1 compared to the control. Generally, the results indicated that applying SNP reduced the effects of water-deficit stress on oilseed rape.