Variation in methanotrophic bacterial population along an altitude gradient at two slopes in tropical dry deciduous forest     

Deen Dayal Giri  Prabhu Nath Shukla  Priti Singh  Kapil Deo Pandey 《Soil biology & biochemistry》2007,39(9):2424-2426

Soil samples were collected from Panchamarhi dry deciduous forest in Satpuda Biosphere Reserve, India to determine the effect of hill slopes and altitude on the population size of methanotrophic bacteria. Population size, in range of 4×10⁵-3.6×10⁷ g⁻¹ dry soil, was negatively correlated with altitude and increased exponentially (r²=0.97, P<0.001) at steep slope (60°) while logarithmically (r²=0.97, P<0.001) at low slope (45°). Soil organic C, total N, and soil moisture increased while C/N ratio and temperature decreased down the hill slope. The results indicated that nutritional status of the soil across the slopes determines the methanotrophic bacterial population size.  相似文献   

Improving nitrogen and phosphorus use efficiencies through inclusion of forage cowpea in the rice–wheat systems in the Indo-Gangetic Plains of India     

B. S. Dwivedi  Arvind K. Shukla  V. K. Singh  R. L. Yadav 《Field Crops Research》2003,80(3):167-193

In high productivity zones of Indo-Gangetic Plains in south Asia, the rice–wheat system is stressed due to production fatigue as evidenced by declining soil organic matter content, low efficiency of fertilizer use and diminishing rates of factor productivity. We, therefore, conducted field experiments at Modipuram, India, to conserve soil organic carbon, improve N and P use efficiency, and increase yields of rice–wheat system through inclusion of forage cowpea during the summer before cultivating the rice–wheat system. Cowpea forage harvested at 50 days removed greater amounts of N and P through aboveground biomass than those recycled through belowground roots and nodules. The NO₃-N in soil profile below 45 cm depth after wheat harvest was greater under fallow during summer than under cowpea, suggesting that cowpea minimized NO₃-N leaching beyond 45 cm depth. Similarly, in the treatments receiving both 120 kg N and 26 kg P ha⁻¹, NO₃-N in soil below 45 cm depth was lower compared to those receiving N or P alone. After three crop cycles, soil OC content in 0–15 and 15–30 cm depths was greater compared to initial OC in plots having cowpea. P applied at 26 kg ha⁻¹ increased available P content over initial P content, and also over P content of soil under no P treatments. The available P content was, however, invariably low under summer cowpea plots as compared to that under no cowpea ones. With continuous rice–wheat cropping, the bulk density (BD) of soil increased over the initial BD at different profile-depths, more so at 30–45 cm depth in no cowpea plots, but inclusion of summer cowpea helped decreasing the BD in the surface (0–15 cm) and sub-surface (15–30 and 30–45 cm) soil layers. Summer cowpea grown on residual fertility after wheat harvest did not influence rice yield, but increased wheat grain yield (P<0.05 during the terminal year), when both the crops received fertilizer N and P at recommended rates. Skipping of N or P or both, however, resulted in consistently low yield of these crops under summer cowpea treatments than those under no cowpea treatments, although the differences were not necessarily significant every year. The use efficiency of applied N and P fertilizers in rice and wheat, measured as agronomic efficiency and apparent recovery, was increased with the use of fertilizer N and P at recommended rates, and also with inclusion of summer cowpea.  相似文献   

Influence of thiobencarb and fluchloralin on the soil and rhizosphere microflora of potato     

A. K. Shukla  B. K. Tiwari  R. R. Mishra 《Potato Research》1992,35(1):41-47

Summary Spray application at locally recommended rates of the herbicides thiobencarb and fluchloralin to potatoes reduced the rhizosphere and general soil microbial populations. Within 30 days the populations had generally recovered although there were some changes in the species composition of the fungal community that persisted until the final sample at harvest time.  相似文献   

Improving rhizospheric environment and sugarcane ratoon yield through bioagents amended farm yard manure in udic ustochrept soil     

S.K. Shukla  R.L. Yadav  Archna Suman  P.N. Singh 《Soil & Tillage Research》2008,99(2):158-168

A field experiment was conducted for two crop cycles during 2003–2005 and 2004–2006 at the Indian Institute of Sugarcane Research, Lucknow in subtropical India. Trichoderma viride and Gluconacetobacter diazotrophicus amended farm yard manure (FYM) increased organic carbon (19.44 Mg ha⁻¹) and available nitrogen (260 kg N ha⁻¹) content of soil from 14.78 Mg ha⁻¹ (OC) and 204 kg N ha⁻¹ observed under farmer's practice (sole N application). Application of bioagents amended FYM improved soil porosity and reduced compaction (bulk density—1.39 Mg m⁻³ over 1.48 Mg m⁻³ under farmer's practice). Sugarcane ratoon crop removed the highest amount of nitrogen (N—165.7 kg ha⁻¹), phosphorus (P—24.01 kg ha⁻¹) and potassium (K—200.5 kg ha⁻¹) in the plots receiving FYM with Trichoderma and Gluconacetobacter. Inoculation of FYM with bioagents improved population of ammonifying and nitrifying bacteria in the soil. Phosphorus and potassium uptake of the crop was greatest in the plots receiving FYM, Trichoderma and Gluconacetobacter. Bioagents (Trichoderma and Gluconacetobacter) amended FYM increased ratoon cane (70.2 Mg ha⁻¹) and sugar yields (7.93 Mg ha⁻¹) compared with control (62.3 and 7.06 Mg ha⁻¹ ratoon cane and sugar yields, respectively).  相似文献   

Deep Tillage,Soil Moisture Regime,and Optimizing N Nutrition for Sustaining Soil Health and Sugarcane Yield in Subtropical India     

S. K. Shukla  R. L. Yadav  Rajendra Gupta  Akhilesh Kr Singh  S. K. Awasthi  Asha Gaur 《Communications in Soil Science and Plant Analysis》2018,49(4):444-462

A field experiment was conducted at ICAR-Indian Institute of Sugarcane Research, Lucknow, with three tillage practices (T₁: Control- two times ploughing with harrow and cultivator, each followed by planking before sugarcane planting; T₂: Deep tillage with disc plough (depth 25–30 cm) before planting followed by harrowing, cultivator, and planking; and T₃: Subsoiling at 45–50 cm and deep tillage with disc plough/moldboard plough (depth 25–30 cm) followed by harrowing, cultivator, and planking before planting, two soil moisture regimes (M₁: 0.5 irrigation water (IW)/cumulative pan evaporation (?CPE) ratio and M₂: 0.75 IW/CPE ratio) at 7.5 cm depth of IW, and four N levels (N₁- 0, N₂- 75, N₃- 150, and N₄-225 kg N ha^?1) in sugarcane plant crop. Deep tillage and subsoiling increased porosity and reduced bulk density in surface/subsurface soil. Further, these physical changes also improved soil biological and chemical properties responsible for higher crop growth and yield. Deep tillage and subsoiling reduced the compaction by 6.12% in 0–15 cm depth in sugarcane plant crop at maximum tillering stage. The highest N uptake (158.5 kg ha^?1) was analyzed with deep tillage and subsoiling compared to all other tillage practices. Maintaining suboptimal moisture regime with deep tillage and subsoiling showed the highest IW use efficiency (157.16 kg cane kg^?1 N applied). Mean soil microbial biomass carbon (SMBC) in ratoon crop was higher compared to plant crop. During initial tillering stage, ratoon crop showed higher SMBC with application of deep tillage and subsoiling (1209 mg CO₂-C g^?1 soil day^?1) at 0–15 cm depth and 1082.9 mg CO₂-C g^?1 soil day^?1 at 15–30 cm depth. Thus, it could be concluded that besides improving sugarcane yield, soil health could be sustained by adopting subsoiling (45–50 cm depth) and deep tillage (20–25 cm depth), with soil moisture regime of 0.75 IW/CPE and application of 150 kg N ha^?1 in sugarcane (plant crop).  相似文献   

Curcuma Dye with Modified Treatment Using Chitosan for Superior Fastness     

Dhara Shukla  Padma S. Vankar 《Fibers and Polymers》2018,19(9):1913-1920

Curcuma dye could never gain popularity in natural dyeing as the intrinsic nature of the colorant Curcumin did not have the requisite adhering property towards natural fabrics such as silk and cotton, thereby making it very fugitive. In this paper attempts have been made to activate Curcumin molecule by complexation with chitosan (another natural linear polysaccharide). The binding took place at intrinsic pH (7–8) very effectively without any surfactant or enzyme. Dyeing with this new composite showed excellent wash and light fastnesses as compared to curcuma dye. The novelty of this dyeing process is the remarkable enhancement of wash and light fastnesses levels by 1.0–1.5 for silk and cotton fabric dyeing in just 1 hour at 40–45 °C. It is fast and energy conserving dyeing process. Three subsequent washing of the dyed samples showed very small change in CIE Lab.  相似文献   

Implications of Gene Actions for Different Qualitative and Quantitative Traits in Linseed (<Emphasis Type="Italic">Linum usitatissimum</Emphasis> L.)     

Anu Rastogi  Sudhir Shukla 《Russian Agricultural Sciences》2018,44(5):434-444

The ninety crosses were evaluated for 27 qualitative and quantitative traits to study the different gene actions, genetic variances, heritability and genetic advances involved in parents and in their off springs. The analysis of variance showed highly significant differences present among all the treatments for all quantitative and qualitative traits. The estimates of genetic component of variances together with related genetic parameters indicated that the magnitude of SCA variances was more pronounced than their corresponding GCA variances for majority of the traits for all testers and lines in both generations which suggested the role of non-additive gene action in the inheritance of these traits. The information obtained from the present study exhibited most of the traits had high value of σ²s than σ²g and over dominance gene action so, it is necessary to maintain the heterozygosity in the population for the improvement purposes. The non-additive genetic variability is non-fixable in nature thus the breeding methods such as biparental mating followed by recurrent selection may accelerate the genetic improvement for the traits sought to be improved.  相似文献