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Pig farming is stepping out from subsistence farming to commercial farming. In order to enhance the commercialized pork production for gaining self-sufficiency, it is necessary to study the production and related parameters of pig at farm level. This study aims to investigate the production parameters and disposal pattern of farm waste adopted by pig farmers in the Punjab. 90 piggery units were surveyed out of which sample size of total of 82 breeding-cum-finisher units of pig were categorized into small farms (< 10 sows), medium farms (10-25 sows) and large farms (> 25 sows). The study reveals that large size category favoured the ideal pig production parameters. It was observed that the 5.17 % of breedable sows were kept on an average for producing finisher pigs for sale (44.60 %). Large category was found having largest average litter size at birth (10.2). Similarly, average weight at saleable age of finisher pig is found to be highest in large size category (102.86 kg). Majority (59.07 %) of the small pig farmers dump the manure at waste heap or dispose it in the sewage posing environmental problems.

A field study with varying nitrogen (N) rates (0-150 kg N ha-1) was conducted in Ludhiana (Punjab, India) in a randomized complete block design in three consecutive baby corn seasons to quantify and mitigate N losses to the environment. The nitrous oxide (N2O) flux emissions were measured at 2, 4, 8, 16, and 24 days after each fertilizer N split application. The leachate N losses were estimated by analyzing ammonium and nitrate ion content. Fertilizer N surplus to crop requirement explained 94.1% (spring), 95.9% (summer), and 95.5% (winter) variation in the area-scaled N losses (N2O, leachate). Lower fertilizer N usage by plants at early growth stages (upto V6 stage) resulted in higher N losses within ten days after the first fertilizer application. Carbon equivalent emissions followed the trend summer> spring>winter. Temporal variations during the monitoring seasons influenced the cob and stover yield in response to fertilizer N. On average, 67.9% of the applied fertilizer N was taken up by plants, 4.7% was lost via N leaching, 2.7% escaped as N2O, 3.2% accumulated in the soil profile, and 21.5% remained unaccounted. Sensing-based N application significantly improved N recovery efficiency by 51.2%, mitigated N emissions by 45.4%, and N leaching by 69.3% in comparison with fixed-time blanket fertilizer N topdressings. Fertilizer N management using PAU-LCC provided an economical and farmer-friendly solution to achieve a significant reduction in N losses while sustaining productivity. Further validation and transfer of technology to on-farm locations are needed to benefit from this work. [ABSTRACT FROM AUTHOR]

Fertilizer nitrogen (N) management in long-grained aromatic basmati rice (Oryza sativa) is critical because both below and above the optimum N application rate adversely affects yield. Multi-location field studies were conducted in northwestern India to formulate a site-specific N management (SSNM) strategy for basmati rice by monitoring the greenness of the fully expanded top leaf of the crop plants using a leaf color chart (PAU-LCC) specially developed at Punjab Agricultural University, Ludhiana. The green colour intensity of the successive panels of PAU-LCC increases with consistent decrease in optical reflectance by 1.6% (at 550 nm wavelength) and thus provides better precision in quantifying leaf colour greenness over the IRRI-LCC (the LCC developed at International Rice Research Institute, Philippines). The threshold leaf greenness at which a variety will respond to fertilizer N was found to be equal to LCC shade 3.5 and 4.0 for less and high N responsive varieties, respectively. Monitoring leaf greenness using LCC at weekly intervals and application of 10 kg N ha−1 whenever leaf greenness was less than the specified threshold level constituted the appropriate SSNM strategy. The SSNM produced grain yield equivalent to soil-test-based fixed N rates but with 20 to 60% less N fertilizer. Significantly higher agronomic (average 40.8 vs. 24.5 kg grain kg−1 N) and recovery (average 76.1 vs. 52.7%) efficiencies of fertilizer N were recorded with SSNM than with soil-test-based fixed fertilizer N rates. The SSNM also reduced N2O and GHG emissions by 20.1 and 23.6% as compared to soil-test-based fertilizer N rates. [ABSTRACT FROM AUTHOR]

Site-specific fertilizer nitrogen (N) management using chlorophyll meter (SPAD meter) can help drawing in-season need-based N topdressing decisions. However, SPAD meter based threshold chlorophyll value to trigger supplement N in spring maize is indistinct. Field studies were conducted for two years in sub-tropical and sub-humid climate to study variations in spectral properties and to establish threshold SPAD value for need-based N management in spring maize cultivars. Results specified that N concentration of topmost fully expanded leaf was closely correlated with SPAD meter readings from six-leaf stage (V6) to tasseling stages (VT). The Cate-Nelson plot expressed SPAD 50 as the threshold value to determine plant N need at different growth stages. Need-based topdressings of 30 kg N ha−1, whenever SPAD reading fell below the threshold 50 improved grain yield production by 7.6 to 10.2 per cent over soil test-based N application. SPAD threshold 45 guided N management was inadequate to meet plant N demand, whereas SPAD threshold 55 guided N application lead to N doses in excess of crop requirement without yield benefits. SPAD threshold 50 guided N management ensured better demand-supply synchrony throughout the growth stages and thus reported better N recovery and agronomic efficiencies over soil test-based N management. [ABSTRACT FROM AUTHOR]

Canopy reflectance measurements using active optical sensors have emerged as potential solution to draw in-season nitrogen (N) topdressings in cereals. Site-specific need-based N management strategy using a GreenSeeker optical sensor was developed and evaluated in spring maize. Four field experiments were conducted at two locations during 2017 and 2018 to develop an algorithm, and two experiments during 2019 to validate the sensor-based application for improving N use efficiency (NUE) and grain yield. The sensor measurements made at V9 growth stage with R2 value of 0.61 obtained from the relation between in-season estimate of yield (INSEY) and grain yield rendered better corrective N rate for improving NUE and getting optimum grain yield, whereas sensor measurements at V6, V12 and VT growth stages were not reliable for the purpose. Applying N rate in two splits of 30 kg N ha−1 at planting and 45 kg N ha−1 at V6 growth stage was recommended before applying sensor based corrective N rate at V9 stage. Sensor guided N topdressing produced yields similar to those obtained by following the soil test-based N recommendations but with lower N rates. These results were also reflected in considerable increase in N recovery (8 _18%) and agronomic (4 _13.5 kg grain kg−1 N) efficiencies in comparison with soil test-based N recommendations, thereby signifying the usefulness of the sensor-based algorithm in optimizing need-based fertilizer N management in spring maize. [ABSTRACT FROM AUTHOR]

A 4 years field study was conducted to improve nitrogen (N) and phosphorus (P) use efficiencies in wheat (Triticum aestivum L.) using arbuscular mycorrhizal fungi (AMF) and precision N management. Split plot design was employed to rationalize N and P fertilizer use in two different experiments with AMF in the main plot and fertilizer application practice in the subplots. The AMF seed coating improved mycorrhization, root dry weight and P uptake. AMF coating of wheat seeds improved mean grain yield and agronomic efficiency of applied P fertilizer (AEP) by 11% and 55.4%, respectively. However, AMF seed coating did not improve chlorophyll content, normalized difference vegetative index, grain yield and agronomic efficiency of applied N fertilizer (AEN). Precision N management using leaf color chart (LCC), chlorophyll meter (SPAD), and GreenSeeker optical sensor (GS) sustained wheat grain yield equivalent to the soil-test based N fertilizer recommendation with 20–31 kg ha−1 less fertilizer N. Proximal sensing guided N use improved AEN by 21.9%–39.6% while mitigating global warming potential by 16%–24%. Integrated use of AMF seed coating and precision N management provides a potential solution to improve N and P nutrition and reduce environmental footprints of fertilizer N use in wheat. [ABSTRACT FROM AUTHOR]

Wheat is grown on more than 240 million hectares globally, more than any other commercial crop. Variation for nitrogen-use efficiency (NUE) in wheat germplasm is very important as efficiency of nitrogen fertilizers use can have significant effect on overall consumption of N. In the present study we used nested synthetic hexaploid wheat introgression libraries to detect genetic variation associated with NUE and related traits. The libraries were genotyped with 9474 SNP markers and used for genome-wide association mapping. Significant phenotypic variation was observed for all measured and derived traits. We detected 10 Quantitative trait locus (QTL) and 19 marker-trait associations (MTAs) possibly involved in improving NUE. Of these, 5 QTL and 8 MTAs detected under nitrogen-limited conditions have potential for use in breeding to increase nitrogen-deficiency tolerance. Nitrate transporter genes collocated with detected MTAs showed significant changes in expression of TaNRT2 genes in response to N-starvation and N-recovery. The identified promising breeding lines with stable yield, better NUE and acceptable protein content may constitute an important genetic resource in improving NUE of modern wheat varieties. • To meet future wheat production demands, improving nitrogen use while maintaining grain yield is vital. • We identified marker-trait associations improving nitrogen use efficiency while maintaining grain yield under varying nitrogen levels. • We also identified promising breeding lines with significant genetic variations and carrying the trait-associated markers or candidate genes. • These may serve as potential donors to be exploited further in genomics-assisted breeding programs targeting improved NUE while maintaining grain yield in wheat. [ABSTRACT FROM AUTHOR]