Impact of 28 year old agroforestry systems on soil carbon dynamics in Eastern Himalayas

Globally, various estimates are available on the above-ground (plant parts) carbon (C) sequestering potential of agroforestry systems (AFSs). However, information on soil organic carbon (SOC) sequestration potential is limited for AFSs. Furthermore, the impacts of AFSs established for the restoration of C in degraded soils (prone to soil erosion, C and nutrients loss, etc.) of Himalayas are rarely investigated. Thus, a study was conducted on an agroforestry block established in 1989 at the Indian Council of Agricultural Research (ICAR), Research Complex for North Eastern Hill (NEH) Region, Lembucherra, Tripura, India. The AFSs comprised of four multipurpose tree species viz., teak (Tectona grandis Linn), sissoo (Dalbergia sissoo Roxb. Ex DC.), eucalyptus (Eucalyptus globulus L.), and neem (Azadirachta indica A. Juss) in combination with pineapple (Ananas comosus L. merr.). Planted in three times replicated randomized block design. After 28 years of establishment, the impacts of these AFSs were assessed on SOC stocks and its fraction pools. Results revealed that sissoo + pineapple system stored the highest SOC stocks in 0-15 cm (22.1 ± 1.4 Mg/ha) and 30-60 cm (18.0 ± 4.3 Mg/ha) depths, whereas the SOC stocks in 15-30 cm (12.2 ± 1.2 Mg/ha) and 0-30 cm (34.0 ± 1.6 Mg/ha) were the highest under teak + pineapple. When considering the entire 0-100 cm soil profile, the SOC stocks ranged between 65.3 and 71.6 Mg/ha across the diverse AFSs which was significantly higher than that under cultivated land (52.8 ± 2.6 Mg/ha). The sissoo + pineapple system had the highest SOC stock in 0-100 cm (71.6 ± 5.8 Mg/ha). The share of passive carbon (PC, less labile + non-labile) pools to SOC stocks under AFSs followed the order of sissoo + pineapple > teak + pineapple > neem + pineapple > eucalyptus + pineapple. The PC or recalcitrant pools of SOC stocks at 0-100 cm were 54.2-60.6% under various AFSs. Results revealed that the establishment of AFSs with pineapple on degraded lands increased a significant amount of C and had a considerable effect on soil quality in comparison to C present in soils under cropland. Thus, a large scale adoption of AFSs may restore C lost through the cultivation of the crop in degraded lands and provide a feasible option for livelihood through concurrent cultivation of multipurpose tree species and agri-horticulture crops.

Performance evaluation of the parents of the improved backyard poultry germplasm in sub-tropical condition of North Eastern Hill Region of India

Productivity of traditional backyard poultry in developing countries can be enhanced by introduction of improved germplasm of backyard chicken which is adaptable to diverse ago-climatic condition. The growth and reproductive performance of parents of improved backyard chicken (Vanaraja and Srinidhi) were evaluated under intensive production system in humid sub-tropical region of North East India. We also evaluated the growth performance and mortality in terminal crosses of above parents until 6 weeks of age. At day 0 and at 25 weeks of age, body weight of Srinidhi male parent was significantly (P<0.05) higher than Vanaraja male parent. During brooding stage, mortality was 15.7% in Srinidhi male parent, 14.5% in Vanaraja male parent, 13.9% in Srinidhi female parent, and 8% in Vanaraja female parent. Hen-day egg production (HDEP) of Vanaraja female parent varied from 0.2 at 25 weeks to 54.9% at 54th weeks of age. In Srinidhi female parent, HDEP reached 60% at 35 weeks and peaked 63.9% at 39 weeks of age. Srinidhi female parent has significantly (P<0.05) lower age at first lay. Average annual egg production was significantly (P<0.05) higher in Srinidhi female parent (202 eggs vs. 137 eggs). Egg weight at 25, 30, 35, 40, 45, and 50 week of age was significantly (P<0.05) higher in Vanaraja female parent. Egg shape index and yolk index at 40 weeks of age were significantly (P<0.05) higher in Srinidhi female parent. Fertility of Vanaraja female parent was significantly (P<0.05) lower in winter. In case of Srinidhi female parent, fertility was significantly higher (P<0.05) in winter as compared to summer. In case of terminal crosses, body weight at 6 weeks of age was significantly (P<0.05) higher in Vanaraja as compared to Srinidhi. Cumulative mortality during brooding phase was 9.2 per cent in Vanaraja and 9.6 per cent in Srinidhi. In conclusion, parents of Vanaraja and Srinidhi are suitable and well-adapted birds in humid sub-tropical condition of North East India. These birds could be introduced in the region on large scale for up-scaling of traditional backyard poultry.

Productive and reproductive performances of two-breed and three-breed pig crosses with Niang Megha, Hampshire and Duroc inheritance reared under subtropical Eastern Himalayan hilly climate

The objective of the study was to evaluate the performance of different crossbreeds, viz., two-breed crosses including HN-50 (50% Hampshire × 50% Niang Megha) and HN-75 (75% Hampshire × 25% Niang Megha) and three-breed cross, HND (25% Hampshire × 25% Niang Megha × 50% Duroc) for suggesting suitable crossbred pigs with appropriate inheritance for subtropical Eastern Himalayan hilly climate. These crossbreed pigs were reared in standard management conditions in Nucleus Pig Breeding Farm of ICAR RC for NEH region. A total of 1995 records were collected which included data on production performance (n = 1466), reproductive performance (n = 428) and carcass traits (n = 101) from farm record book maintained over a period of 7 years. Productive performance included body weight, ADG and FCR at different stages of growth. The study revealed productive performance was highest in two-breed cross of pigs with 75% H inheritance (HN-75) and three-breed cross (HND) pigs. Reproductive performance included ages at puberty, first conception and first farrowing, along with inter-farrowing interval, pregnancy and farrowing rate as well as litter performance. The HN-75 was found to be having shorter inter-farrowing interval and higher pregnancy rate than other genetic groups. Regarding carcass traits, three-breed cross had a higher dressing percentage and less back-fat thickness than other crossbred pigs. Two breed crosses of pigs were found to be having a higher back-fat thickness than three-breed cross pig, and HN-75 had a better dressing percentage than HN-50. Thus, it was concluded that three-breed cross was recommended for lean meat production, and two-breed cross HN-75 was recommended for both breeding and fattening purposes for subtropical Eastern Himalayan hilly climate.

Dietary flaxseed oil improve boar semen quality, antioxidant status and in-vivo fertility in humid sub-tropical region of North East India

Environmental stress in the form of high temperature humidity index (THI) in tropical and sub-tropical region negatively affects semen quality and fertility of boar. Therefore, the present study was done to evaluate the effect of supplementing flaxseed oil (FLO) to boar's diet on its semen quality, antioxidant status, fatty acid composition of seminal plasma and fertility under sub-tropical climate. For this purpose, six Hampshire crossbreed (50% Hampshire and 50% Gunghroo) boars were divided into two groups i.e control (CON) and treatment (FLO). In FLO and CON group, flaxseed and vegetable oil, respectively, was top dressed at the rate of 3% in basal diets for each boar on daily basis for 16 weeks during monsoon season. A total of 60 ejaculates, comprising 30 ejaculates from each group (ten ejaculates from each boar) were collected. Semen samples were evaluated for sperm quality parameters (SQPs: motility, viability, abnormality, acrosomal integrity and Hypo-osmotic swelling test) and velocity attributes by computer assisted semen analysis (CASA) at fresh and after 72 h of preservation at 17 °C. Antioxidant (glutathione peroxidase; GPx, catalase; CAT, total antioxidant capacity; TAC and malondialdehyde; MDA) were analyzed in seminal plasma and serum. Fatty acid compositions of seminal plasma were analyzed by gas chromatography-mass spectrometry (GC-MS). In-vivo fertility study was also conducted. Reaction time and false mounts were significantly (p < 0.05) reduced in FLO group as compared to CON group. Semen quality parameters were significantly (p < 0.05) improved at fresh stage and after 72 h of liquid storage in FLO group as compared to CON group. Velocity attributes (VAP, VSL, VCL, ALH, BCF and LIN) were significantly (p < 0.05) higher in FLO group. Flaxseed oil supplementation significantly (p < 0.01) enhanced serum GPx and CAT concentration. Serum and seminal plasma MDA concentration decreased significantly (p < 0.01) in FLO group. Similarly, GPx, TAC and CAT were significantly (p < 0.01) elevated in seminal plasma of FLO group. The study revealed that feeding of flaxseed oil altered the fatty acid composition of seminal plasma and significantly (p < 0.05) improved the farrowing rate. In summary, flaxseed oil supplementation improved the semen quality parameters and fertility of boars in sub-tropical climate by improving the antioxidant capacity and altering the fatty acid composition of seminal plasma.

Prevalence, molecular typing and antibiotic resistance of Clostridium perfringens in free range ducks in Northeast India

This study reports faecal prevalence of Clostridium perfringens in free range ducks in North East India for the first time. We also report C. perfringens type A carrying cpb2 and cpe and type C carrying cpb2 and cpe strains in these ducks. Notably, a high prevalence (17.5%) of enterotoxin carrying C. perfringens strains and low antimicrobial resistance were observed.

Pea (Pisum sativum l.) Plant Shapes Its Rhizosphere Microbiome for Nutrient Uptake and Stress Amelioration in Acidic Soils of the North-East Region of India

Rhizosphere microbiome significantly influences plant growth and productivity. Legume crops such as pea have often been used as a rotation crop along with rice cultivation in long-term conservation agriculture experiments in the acidic soils of the northeast region of India. It is essential to understand how the pea plant influences the soil communities and shapes its rhizosphere microbiome. It is also expected that the long-term application of nutrients and tillage practices may also have a lasting effect on the rhizosphere and soil communities. In this study, we estimated the bacterial communities by 16S rRNA gene amplicon sequencing of pea rhizosphere and bulk soils from a long-term experiment with multiple nutrient management practices and different tillage history. We also used Tax4Fun to predict the functions of bacterial communities. Quantitative polymerase chain reaction (qPCR) was used to estimate the abundance of total bacterial and members of Firmicutes in the rhizosphere and bulk soils. The results showed that bacterial diversity was significantly higher in the rhizosphere in comparison to bulk soils. A higher abundance of Proteobacteria was recorded in the rhizosphere, whereas the bulk soils have higher proportions of Firmicutes. At the genus level, proportions of Rhizobium, Pseudomonas, Pantoea, Nitrobacter, Enterobacter, and Sphingomonas were significantly higher in the rhizosphere. At the same time, Massilia, Paenibacillus, and Planomicrobium were more abundant in the bulk soils. Higher abundance of genes reported for plant growth promotion and several other genes, including iron complex outer membrane receptor, cobalt-zinc-cadmium resistance, sigma-70 factor, and ribonuclease E, was predicted in the rhizosphere samples in comparison to bulk soils, indicating that the pea plants shape their rhizosphere microbiome, plausibly to meet its requirements for nutrient uptake and stress amelioration.