Influence of in-house produced biochars on cracks and retained water during drying-wetting cycles: comparison between conventional plant,animal, and nano-biochars

Purpose

Biochars produced from different feedstocks (such as wood, pig manure) possess varying physical and chemical properties, which have influence on crack and evaporation rate of biochar-amended soil (BAS). Furthermore, influence of compaction state and drying-wetting cycles on evaporation rate and cracking of BAS has not been investigated comprehensively. The objective of this study was to investigate the effects of biochar types, compaction state of BAS, and drying-wetting cycles on crack propagation and retained water (or evaporation rate).

Material and methods

An animal and plant feedstock-based biochars were produced in-house from pig manure (PM) and wood (W), respectively. In addition, nano structured chalk and wheat biochar (CWB) were also produced. Soil amended with individual biochars was compacted in petri-glass discs at two densities. Disc specimens were subjected to multiple drying-wetting cycles, and evaporation rate of specimens and crack area were monitored throughout the experimental period (70 days). Images were captured after every 24 h and processed using image processing technique to obtain the crack intensity factor (CIF).

Results and discussion

The results show that plant-based W BAS showed the high water retention, i.e., low evaporation rate and low CIF. Furthermore, the crack potential of CW BAS was seen to be higher. In dense compacted soil, maximum CIF% can be reduced from 3.9 to 0.4% for W BAS, from 3.9 to 1.7% for PM BAS, and from 3.9 to 1.6% for CW BAS.

Conclusion

WB was able to resist cracking more efficiently than other types of biochar. Evaporation was found to be minimal for plant-based W BAS at 10% biochar percentage. Higher biochar content in soil was seen to increase the water retention of BAS significantly. Dense state of BAS at high biochar content (i.e., 10%) was effective in reducing evaporation rate and crack progression.

     

Effect of Seed Size on Germination and Seedling Growth in Greengram (Vigna radiata L. Wilczek) and Blackgram (Vigna mungo L. Hepper) Cultivars

The effect of seed size on germination and seedling growth was assessed using cultivars of greengram and blackgram. Significant positive correlation was noticed between seed size and germination, seedling height, root length, primary leaf size and seedling weight. The possible advantages of choosing cultivars with heavier seeds for attaining better crop stand especially under rainfed situation are discussed.     

Anthelmintic activity of Butea monosperma

The methanol extract of Butea monosperma seeds, tested in vitro, showed significant anthelmintic activity.     

Status of floor vegetation under some monoculture and mixculture plantations in North India

A study conducted to assess the floor vegetation shows the presence of 17 species underPopulus deltoides in comparison to 28, 29 and 35 underAlbizia lebbeck, Dalbergia sissoo and mix-culture plantations, respectively. Further, the biomass and density of floor vegetation is considerably reduced underP. deltoides compared to other plantations. In addition, the indices for species richness, evenness, dominance and diversity are also reduced underP. deltoides showing some inhibitory mechanism being operative under these plantations. Based on available literature, allelopathy is speculated to be responsible for this reduction.     

New gingerdione from the rhizomes of Zingiber officinale

A new gingerdione has been isolated from the rhizomes of Zingiber officinale and identified as 1-dehydrogingerdione (1).     

Dynamic adsorption of α-pinene and linalool on silica nanoparticles for enhanced antifeedant activity against agricultural pests

The terpene compounds, α-pinene and linalool were formulated with silica nanoparticles (SNPs) by a simple immersion method and the antifeedant activity of these formulations was evaluated against two major agricultural pests, the tobacco cutworm (Spodoptera litura F.) and the castor semilooper (Achaea janata L.) in laboratory bioassays. The interaction between terpenes and SNPs, shelf-life, suspension stability as well as the bioactivity of the nanoformulations were also studied. Both these terpenes in their pure form are known to deter feeding in several lepidopterous insects. However, formulating these pure terpene compounds with nano silica enhanced their biological activity up to 25 times to S. litura. Fourier transform infrared spectroscopy analysis of these nano botanical formulations indicated the presence of hydrogen bonding between terpenes and the surface of SNPs. Transmission electron microscopy images confirmed the higher aggregation property of the SNPs. Suspension studies validated the improved shelf-life of the nano-biocomposites, while X-ray diffraction (XRD) revealed the amorphous nature of formulations and no crystalline impurities. Adsorption of α-pinene and linalool onto SNPs resulted in an effective formulation that enhanced the antifeedant potential of the individual terpenes against insects while producing longer shelf-life for the terpenes.     

Effects of temperature, salinity and pH on larval growth, survival and development of the sea cucumber Holothuria spinifera Theel

For large-scale seed production of sea cucumbers through a hatchery system, it is imperative to know the effects of environmental parameters on larval rearing. Auricularia larvae (48 h post-fertilization) were obtained from induced spawning of Holothuria spinifera and used in experiments to ascertain the effects of temperature, salinity and pH on the growth and survivorship of the larvae. The larvae were reared for 12 days at temperatures of 20, 25, 28 and 32 °C; salinities of 15, 20, 25, 30, 35 and 40 ppt; and pH of 6.5, 7.0, 7.5, 7.8, 8.0, 8.5 and 9.0. The highest survivorship and growth rate and fastest development of auricularia indicated that water temperature of 28–32 °C, salinity of 35 ppt and pH of 7.8 were the most suitable conditions for rearing larvae of H. spinifera.     

Lagenidium callinectes (Couch, 1942) infection and its control in cultured larval Indian tiger prawn, Penaeus monodon Fabricius

A mycosis in larval tiger prawn, Penaeus monodon Fabricius, is described for the first time from India. The hyphae of Lagenidium callinectes are contorted, irregularly branched, sparingly septate, and contain a cell wall and membrane, vacuoles, mito chondria, ribosomes, small and large vesicles, and Woronin bodies. The spores occur singly or in pairs. The fungal mycelium may either invade and embed itself in the tissues, or alternatively, replace all the muscle tissues of the infected larval P. monodon. Fungus infected, untreated populations of nauplii, zoea and myksis exhibited mortalities of 5.33 ± 0.55%, 24.68 ± 4.58% and 47.89 ± 0.27%, respectively. A 0.5 ppm treatment with trifluralin significantly reduced the mortality of infected larval populations (i.e. 1.1% nauplii, 3.28% zoea and 5.21% myksis mortality). Lagenidium sp. exhibited growth in potato dextrose agar medium and in Sabouraud's agar at 28 °C.