Navneet Pareek

Biochar and crop residue application to soil: effect on soil biochemical properties, nutrient availability and yield of rice (Oryza sativa L.) and wheat (Triticum aestivum L.)

ABSTRACT In the recent past, biochar and crop residues have attracted lots of attention as a viable strategy for maintaining soil health. This paper evaluates the comparative effect of two different doses (equivalent to 2 and 5 t C ha−1) of each of pine needle and Lantana biochar (PBC and LBC), wheat residue and lentil residue (WR and LR) on soil biological properties, nutrient availability and yield of rice and wheat in pot culture. Energy-dispersive X-ray spectroscopy (EDS) revealed higher C content of biochar than crop residues. Evaluation of biochemical quality reflected high recalcitrance indices of C and N for both PBC and LBC. Application of LBC and PBC increased the wheat grain yield significantly by 6.2%–24.2% over control. Both PBC and LBC significantly increased N and P uptakes in grain over the control and crop residues. Both biochars recorded a significant decrease of 33.9 and 71,7% in β-glucosidase activity in comparison to control at termination of study. PBC and LBC also resulted in more soil available N, P and K in soil at different intervals. The geometric mean of enzyme activities (GMea) reflected improved soil quality by PBC and LR and reduction by LBC application.

Long-term effects of fertilization and manuring on productivity and soil biological properties under rice (Oryza sativa)–wheat (Triticum aestivum) sequence in Mollisols

ABSTRACT Long-term effects of chemical fertilizers and farmyard manure (FYM) in rice (Oryza sativa)–wheat (Triticum aestivum) cropping system were monitored for two consecutive years after 38 and 39 years on productivity and soil biological properties of Mollisols. The study encompasses varying chemical fertilizer levels of optimum fertilizer rate (120, 26 and 37 kg ha−1 N, P and K, respectively) for both the crops. The treatments were application of 50% NPK, 100% NPK, 150% NPK, 100% NPK + hand weeding (HW), 100% NPK + Zn, 100% NP, 100% N, 100% NPK + 15 t FYM ha−1, 100% NPK(-S) and unfertilized control. The rice and wheat yields were highest with 100% NPK + 15 t FYM ha−1. This treatment also gave maximum and significantly more counts of bacteria, fungi and actinomycetes in soil than all the other treatments after crop harvest. The soil microbial biomass C (410.0 and 407.5 µg g−1) and N (44.53 and 48.30 µg g−1) after rice and wheat, respectively, were highest with 100% NPK + 15 t FYM ha−1, which were significantly higher over all the other treatments. The activities of soil enzymes like dehydrogenase, acid and alkaline phosphatase, arylsulphatase and urease and CO2 evolution rate with 100% NPK + 15 t FYM ha−1 were also found significantly higher over the other treatments. Fertilizer treatments with 100% NPK and 150% NPK were comparable and significantly better than application of 50% NPK, 100% N, 100% NP and 100% NPK(-S) in various studied soil biological properties. Integrated use of 100% NPK with FYM sustained the higher yields and soil biological properties under rice–wheat cropping system in Mollisols. Application of Zn and hand weeding with 100% NPK were found better over 100% NPK alone in rice and wheat productivity. Imbalanced use of chemical fertilizers had the harmful effect on soil biological health.

Effect of foliar application of seaweed saps on chemical soil quality, growth and yield of black gram

A field experiment was conducted to evaluate impact of seaweed (Kappaphycus sp. and Gracilaria sp.) saps on chemical soil health, growth and yield of Vigna mungo. Foliar application of saps was carried out 35 days after sowing and at flowering with four concentrations (2.5, 5, 10 and 15%) of K-sap and G-sap separately, 7.5% of K-sap + 50% RDF and control. At harvest, highest build up of organic carbon was recorded due to 15% K-sap foliar application while highest available N was observed due to 10 and 15% K-sap. Foliar application of 7.5% K-sap + 50% RDF and 5% G-sap supported the highest available P and K in soil at harvest, respectively. At flowering, highest nodule number of 43 plant−1 was recorded due to 5% G-sap. Foliar application of seaweed saps at various concentrations, except 2.5%, enhanced the grain yield by 27.43% over control. The foliar application of 7.5% K-sap + 50% of RDF also produced the 25.73% higher grain yield over control which was at par with those of other treatments, saving 50% of chemical fertilizers vis-a-vis environmental pollution

Impact of biodynamic preparations and panchgavya in organically managed cropping systems comprising legumes on soil biological health

Biological health of soil was assessed to understand the effect of varingly managed organic cropping systems under field conditions. Twelve treatment combinations comprised two cropping systems (CS1-Basmati rice-Chickpea-Sesbania green manure ;CS2-Basmati rice-Vegetable pea-Maize (green cob & Fodder) + Green gram (residues incorporation) and six organic nutrient manangement practices- T1: Farmyard manure + Vermicompost + Enriched Compost + Neem Cake, T2: Biodynamic Preparations, T3: Farmyard manure + Vermicompost + Enriched Compost + Neem Cake + Panchgavya, T4: Farmyard manure + Vermicompost + Enriched Compost + Neem Cake + Biodynamic Preparations, T5: Farmyard manure + Vermicompost + Enriched Compost + Neem Cake + Biodynamic Preparations + Panchgavya, T6: Control. The highest activity of different soil enzymes viz., dehydrogenase, acid, alkaline and total phosphatase; and aryl sulfatase was assessed to the tune of 1311.02 µg Tri Phenyl Formazan 24h-1g-1 soil at flowering in ‘spring’, 26.99 µg p-nitrophenol h-1g-1 soil, 35.19 µg p-nitrophenol h-1g-1 soil, 62.18 µg p-nitrophenol h-1g-1 soil and 77.75 µg p-nitrophenol h-1 g-1 soil at harvest of ‘rabi’ crop, respectively receiving the organic nutrient package through T5. Significantly enhanced microbial population and their biomass facilitating the enhanced mineralization of nitrogen to the tune of 150.10 µg NH4+-N g-1 soil with nutrient management practices employed through T5 was observed.

Co-inoculation Effect of Endophytic Bacteria with Mesorhizobium sp. in Chickpea (Cicer arietinum L.) on Nodulation, Yields, Nutrient Uptake and Soil Biological Properties

Performance of 10 different endophytic bacteria on the root nodulation, growth and yields of chickpea and soil properties was evaluated in a field experiment during rabi season of 2013–2014 in a sandy loam soil at Pantnagar. Thirty-three endophytic bacterial strains were isolated from the roots and nodules of chickpea grown in different plots at Norman E. Borlaug Crop Research Centre of G.B. Pant University of Agriculture and Technology, Pantnagar. Mesorhizobium sp. alone showed marginal benefits in nodulation, plant dry matter production, grain and straw yields, N and P uptake and soil biological properties. Combined use of Mesorhizobium sp. with different endophytic bacteria further increased the nodule number by 4.7 to 81.8 per cent, nodule dry weight by 2.3 to 69.3 per cent, and plant dry weight by 2.4 to 66.5 per cent, over Mesorhizobium sp. alone inoculation at different crop stages. Endophytic bacteria NE10 and NE14 also recorded significantly more grain yield of 18.4 and 17.1 per cent and straw yield of 26.1 and 27.7 per cent over Mesorhizobium sp. alone. The co-inoculated endophytic bacteria improved N uptake by grain from 16.1 to 44.3 per cent, N uptake by straw from 3.3 to 43.5 per cent, P uptake by grain from 10.5 to 39.7 per cent and P uptake by straw from 5.8 to 66.9 per cent over Mesorhizobium sp. alone. Combined inoculation of endophytic bacteria NE3, NE5, NE10, NE12, NE14, NE16, NE17 and R4 recorded significantly more microbial biomass carbon in soil over Mesorhizobium sp. alone at 45 days after sowing and harvest of crop. The co-inoculated endophytic bacteria also favoured the soil dehydrogenase and acid and alkaline phosphatase activities at both the intervals. The NE 10 was found most efficient in improving the nodulation, plant dry matter, yield, nutrient uptake and soil biological properties.

Effect of Varying Rates and Methods of Carrier based and Liquid Azotobacter and PSB Biofertilizers on Yield and Nutrient Uptake by Wheat (Triticum aestivum L.) and Soil Properties

A field experiment was conducted during 2012–13 and 2013–14 in Mollisol at Pantnagar to examine the effects of varying rates and methods of application of carrier based and liquid Azotobacter and PSB biofertilizers in combination with chemical fertilizers in wheat (Triticum aestivum L.). Application of 100% NP showed maximum plant height, grain and straw yields, nutrient uptake and available NPK in soil after harvesting. Soil application of carrier biofertilizer at 10 kg ha−1 and liquid biofertilizer at 0.625 and 1.25 L ha−1 in combination with 75% NP gave significantly more plant height over 75% NP alone at different intervals. These treatments were at par with 100% NP alone in plant height and grain and straw yields. The mean grain yield due to soil application of carrier biofertilizer at 10 kg ha−1 and liquid biofertilizers at 0.625 and 1.25 L ha−1 with 75% NP was significantly more by 10.9, 10.5 and 10.8 per cent over 75% NP alone, respectively. The respective increases in mean straw yield due to these treatments were 8.6, 8.2 and 9.1 per cent, respectively over 75% NP alone. The trend that observed in grain and straw yield was also observed in various yield attributes viz., total tillers, effective tillers, ear length, and number of spikelet/ear, number of grains/ear and 1000 grain weight. These treatments also significantly increased N, P and K uptake by grain and straw. All biofertilizer treatments with 75% or 50% NP gave significantly more available NPK in soil after harvesting over respective doses of NP alone. The different biofertilizer treatments with 50% NP also showed similar positive response for growth, yields, nutrient uptake and available NPK in soil in comparison to 50% NP alone. The carrier and liquid formulations of the biofertilzers at respective rates were comparable in their performance. Irrespective of formulation and doses, application of biofertilizers in soil was found better than seed treatment for different recorded parameters. The increasing rates of the carrier and liquid biofertilizers applied in soil slightly improved the various recorded parameters. An application of 0.625 L ha−1 liquid biofertilizers in soil with 75% NP was found optimum for the growth, yield, nutrient uptake and available NPK in soil after harvesting.