Rapid,non-destructive carbon analysis of forest soils using neutron-induced gamma-ray spectroscopy

Forest soils are pivotal to understanding global carbon (C) cycling and evaluating policies for mitigating global change. However, they are very difficult to monitor because of the heterogeneity of soil characteristics, the difficulty of representative sampling, and the slow time scale of response to environmental change. Here we demonstrate that use of gamma-ray spectroscopy facilitates in situ non-destructive analysis of C and other elements in forest soils. In this approach the element-specific gamma-rays are induced by fast and thermal neutrons interacting with the nuclei of the elements present in the soil. Background gamma-rays emanating from naturally occurring radionuclides in the forest are recorded as well. We applied this approach in a mature northern hardwood forest on glacial till soils at the Bartlett Experimental Forest in New Hampshire, USA. The inelastic neutron scattering (INS) system yielded strong signals in gamma-ray counts/h, from C and other elements present in the soil matrix that included silicon, oxygen, hydrogen, iron, aluminum, manganese and potassium. The INS sensitivity for carbon was 20.656 counts h⁻¹ kg⁻¹ C m⁻² based on current net C gamma-ray counts and the data for the O horizon and mineral soil to a depth of 30 cm obtained from a nearby quantitative soil pit (7.35 kg C m⁻²). We estimate the minimum detectable change to be ∼0.34 kg C m⁻², which is ∼5% of the current soil C content, and the minimum detectable limit to be ∼0.23 kg C m⁻². Eight % reproducibility from 11 measurements was limited, in part, by the large variability in the system counting geometry due to the uneven forest microtopography. The INS approach has the potential to revolutionize belowground monitoring of C and other elements, because the possibility of detecting a 5% change in forest soils has not been possible with destructive sampling methods.     

INTERACTION EFFECT OF POTASSIUM AND SULFUR FERTILIZATION ON PRODUCTIVITY AND MINERAL NUTRITION OF SUNNHEMP

The interactive effect of potassium (K) and sulfur (S) fertilization on productivity and mineral nutrition of sunnhemp (Crotalaria juncea L.) was evaluated in a field experiment during 2008 and 2009 cropping seasons at Uttar Pradesh, India. Potassium and sulfur fertilizers increased fiber yield and nutrient uptake of sunnhemp. It was observed that an application of K and S at 40 kg ha^?1 each significantly increased the total dry matter, fiber yield, and nutrient uptake of sunnhemp. The crop yield response to the added S was greater than for K and the nutrient use efficiency was also higher at lower levels of fertilizer addition. The increased levels of K and S improved the number of nodules and crude protein content of sunnhemp leaves.     

Formation of alkali soils by neutral salt solutions

It has been reported that large tracts of land under irrigation in the western part of United States contain enough soluble salts to depress crop production and thousands of acres have been abandoned because of salinity. In soils commonly called white alkali soils, containing accumulation of neutral salts in the form of chlorides or sulphates, 0.2% of salt will reduce yields of salt sensitive plants and 1.0% will cause marked yield reduction in most crops. If the drainage is poor and water table is maintained near the surface of the soil, evaporaLion will be high and the salt will accumulate. When large amount of soluble salts accumulate at the surface, the soil is termed as saline and has a pH value below 8.5. The soils containing alkali salts such as Na.COa or NaHC03 and having a pH value above 8.5 are called alkali soils or black alkali soils. Misra (1954) has reported that a gradual replacement of calcium ions and a subsequent increase in the exchangeable Na or K in the exchange complex of the soil, due to repeated leaching of the soils with dilute salt solutions of Na or K takes place which is similar to the repeated leaching of agricultural fields by irrigation.al water containing smaller amounts of soluble salts of Na or K. He has also reported that K-soils, which are also alkaline, are formed under similar conditions of leaching of the soil with K-salLs. Greater amounts of calcium were found in the filtrate when soluble salts were used instead of water alone for leaching the soil.     

Photosynthesis and Assimilate Partitioning in Mungbean in Response to Source-Sink Alteration

The effect of alteration in source-sink ratio by deflowering and defoliation technique on photosynthesis rate was examined in mungbean ( Vigna radiata [L.] Wilczek) var. PS 16. Deflowered plants where sink demand was decreased, maintained a higher rate of photosynthesis in spite of their higher starch content in the leaves. This treatment also increased the partitioning of assimilates to leaves, stem, roots and nodules indicating the existence of alternative sink capacity. The higher rate of photosynthesis of deflowered plants was associated initially with lower stomatal diffusive resistance and subsequently with higher leaf nitrogen content. Increase in sink demand for a particular leaf by excising other source leaves also increased the rate of photosynthesis. These results are discussed in relation to possible regulation through hormones.     

Identification of sperm motility markers in bovine transition protein genes

Transition proteins (TNPs) are essential in chromatin condensation during spermiogenesis, and hence, they are the candidate genes for identifying sperm motility markers. Coding and in silico predicted promoter regions of these genes were investigated in crossbred and purebred cattle, and also, their mRNA quantification was done to explore its use as a diagnostic tool of infertility. PCR‐SSCP analysis revealed two band patterns in fragment III of TNP1 and fragment II of TNP2 gene. Sequence analysis revealed a deletion of “G” nucleotide in 3′UTR region of TNP1 and C>T SNP in intronic region of TNP2 gene. Least square analysis of variance did not reveal any significant influence of nucleotide deletion on any sperm motility parameters in both crossbred and purebred cattle. However, C>T SNP had a significant effect on initial progressive motility (p < 0.05) in purebred cattle and post‐thaw motility in overall cattle population. RT‐qPCR analysis did not reveal any significant variation in TNP1 and TNP2 gene expression among poorly motile and good quality spermatozoa of Vrindavani bulls.     

Effects of varied levels of incorporation of Labeo gonius in carp polyculture system in India

Growth performance of kuria labeo, Labeo gonius as a component species in the major carp polyculture system was evaluated at two incorporation levels against a control without the species through a year‐round grow‐out study in nine earthen ponds (0.08 ha). Three species ratio of catla, silver carp, rohu, mrigal and kuria labeo at 15:15:40:30:0 (T‐1: control), 15:15:40:20:10 (T‐2) and 15:15:40:10:20 (T‐3) were evaluated as three treatments. The carps were stocked at a combined density of 7500 fingerlings ha^?1. Silver carp demonstrated the highest survival (75–81%) followed by rohu (70–76%), catla (69–76%), kuria labeo (69–71%) and mrigal (67–69%). Species‐wise yield attributes such as survival, harvest weight, SGR and biomass yield of silver carp, catla and rohu were similar in their respective treatments. Kuria labeo at 10% inclusion demonstrated 12% higher harvest weight than its 20% inclusion. However, such higher weight gain could not affect the total biomass yields of carps which remained similar among the treatments. Furthermore, harvest weight of kuria labeo at 10% inclusion was comparable to that of mrigal when the latter incorporated at 20–30% level. Therefore, the study suggested 10% to be a suitable incorporation level for kuria labeo in the commercial grow‐out carp polyculture system.     

Ontogeny of the digestive tract in butter catfish Ompok bimaculatus (Bloch) larvae

The ontogeny of the digestive tract was studied histologically in butter catfish Ompok bimaculatus from hatching to 30?days post-hatching (dph). At hatching, the digestive tract of butter catfish consisted of a straight tube with a smooth lumen dorsally attached to the yolk sac. Between 1 and 2 dph, the mouth opened, oral valves were visible and canine-like teeth and taste buds were detected. During this period, intestine was differentiated into the anterior and posterior intestine, and the digestive accessory glands were also developed. Exogenous feeding started at 2?dph, and there was a 2-day mixed endogenous–exogenous feeding period. Most of the yolk sac reserves were consumed between 2 and 3 dph, and by 5?dph, the yolk sac was completely depleted and no longer visible in histological sections. Between 3 and 4 dph, several vacuoles (neutral lipids) were observed in the intestine and also in hepatocytes, indicating a functional absorption of nutrients from food. At 8 dph, differentiation of gastric glands was noticed, and by 9–11?dph, there were abundant gastric tubular glands arranged along numerous longitudinal folds. During the same period, pyloric sphincter appeared as an epithelial fold that separated the stomach from the anterior intestine. From 12 dph to the end of the study at 30?dph, no noticeable histological modifications were observed. The development of gastric glands is considered as the last major events in digestive tract development and their presence designates the end of larval period and the onset of the juvenile period. Hence, it is suggested that, butter catfish larvae have a morphologically complete digestive tract by 12?dph. These findings on the development of the digestive system in butter catfish may lead to a better understanding of the ontogeny and would be useful to improve the larval rearing techniques of this promising catfish species for freshwater aquaculture diversification.     

Isolation of two cDNAs encoding MHC-DQA1 and -DQA2 from the water buffalo, Bubalus bubalis

In the present study, we explored structural and functional variations and possible duplication of the major histocompatibility complex (MHC)-DQA gene in water buffalo (Bubalus bubalis). Two cDNA sequences, amplified from one individual water buffalo, were designated as Bubu-DQA1 (DQA*0101) and -DQA2 (DQA*2001). The percentage of nucleotide and amino acid similarity between Bubu-DQA1 and -DQA2 revealed that these sequences display more similarity to alleles of respective DQA1 and DQA2 genes from other ruminant species than to each other. The phylogenetic analysis also revealed a considerably larger genetic distance between these two genes than between homologous genes from other species. The larger genetic distance between DQA*0101 and DQA*2001, and the presence of different bovine DQA putative locus specific amino acid motifs, suggests these sequences are non-allelic. This finding is consistent with DQA gene duplication in other ruminants.