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Poor soil organic matter is one of the major causes of the deterioration of soil health. Most soils fertility is also decreased when enough organic carbon is not present in the soil. Maize is most susceptible to this poor soil fertility status. A significant amount of maize growth and yield is lost when it is cultivated in low organic matter and poor fertility soil. To overcome this issue organic amendments can play an imperative role. Biochar and vermicompost are organic amendments that can not only improve organic residues but also increase soil nutrient concentration. The current experiment was conducted to explore the sole and combined application of both organic amendments with recommended NPK fertilizer. Four treatments were tested i.e., control, biochar (BC1), vermicompost (VC1) and VC1+BC1 with and without nitrogen (N), phosphorus (P) and potassium (K) in the experiment. Results showed that VC1+BC1+NPK performed significantly best for improvement in maize plant height (6.25 and 3.00%), 1000 grains weight (30.48 and 29.40%), biological yield (18.86 and 43.12%) and grains yield (30.58 and 39.59%) compared to BC0+VC0+NPK and control respectively. A significant improvement in soil N, P and K also validated the efficacious role of VC1+BC1+NPK over BC0+VC0+NPK and control. Treatment VC1+BC1+NPK is recommended for the achievement of better maize growth and yield in poor organic matter soils. More investigations are suggested in variable climatic conditions to declare VC1+BC1+NPK as the best amendment compared to control for enhancing soil N, P and K status as well as maize productivity.

Arsenic (As) contamination is a serious threat to agriculture and human health worldwide. It can adversely affect the growth attributes of food crops. On the other hand, using thiourea (TU) to ameliorate As stress is an economically consistent approach. However, there is a knowledge gap regarding the combined use of TU and Sewage sludge (SS). SS is considered important, unutilized biomass. It can be used as a fertilizer that has high organic matter and nutrients. Therefore, the current study was performed to evaluate TU and SS sole and combined responses under As toxicity on two wheat genotypes (Markaz 19 and Ujala 16). There were four treatments control (As 50 mg kg-1), SS (30 g kg−1)+TU (6.5 mM)+As, TU+As and SS+As applied with four replications. Results revealed that SS+TU performed significantly better over SS, TU and control for improvement in root and shoot fresh and dry weight of wheat varieties Markaz 19 and Ujala 16 under As toxicity. A significant decrease in POD, SOD and APX of Markaz 19 and Ujala 16 also validated the effective functioning of SS+TU over control. The maximum increase of 71 and 77% was noted in phosphorus, where SS+TU was applied over control in Markaz 19 and Ujala 16, respectively. In conclusion, SS+TU is a better approach than the sole application of SS and TU under As contamination for improvement in wheat growth attributes. More investigations are recommended at the field level under different As contamination and agro-climatic zones to declare SS+TU an effective amendment to mitigate As toxicity in wheat.

We evaluated phytochemical composition, antibacterial, antifungal, anti-oxidant and cytotoxic properties of aqueous (water) and organic extracts (methanol, ethyl acetate and n-hexane) of Chenopodium glaucum. Highest phenolic content 45 mg gallic acid equivalents (GAE)/g d.w was found in aqueous extract followed by ethyl acetate (41mg GAE/g d.w) and methanol extract (34.46 mg GAE/g d.w). Antibacterial potential of aqueous and organic extracts of C. glaucum was examined against Acinetobacter baumannii, Klebsiella pneumoniae, Escherichia coli and Staphylococcus epidermidis. The aqueous, methanolic, ethyl acetate, and n-hexane extract showed antibacterial activity against A. baumannii, K. pneumoniae, E. coli and S. epidermidis. However, against A. baumannii significantly higher inhibition zone (19 mm and 18.96 mm respectively) was shown by ethyl acetate and methanol extracts. Aqueous extract possessed highest growth inhibition (11 mm) against E. coli. Aqueous, ethyl acetate and methanol extracts showed 9 mm, 10 mm, and 10.33 mm zone of inhibition against the K. pneumoniae. For antifungal activity, the extracts were less effective against Aspergillus niger but showed strong antifungal activity against Aspergillus flavus (A. flavus). The antioxidant activity was measured as DPPH (2, 2-diphenyl-1-picrylhydrazyl), H2O2 and ABTS (2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity of free radicals. All the organic extracts of C. glaucum possessed ABTS, DPPH and H2O2 scavenging properties. The highest cytotoxic activity measured as half maximal inhibitory concentration (IC50) against human lungs carcinoma cells was recorded for methanolic (IC50 = 16 μg/mL) and n-hexane (IC50 = 25 μg/mL) extracts, respectively. The Gas chromatography–mass spectrometry (GC-MS) analysis showed 4 major and 26 minor compounds in n-hexane extract and 4 major and 7 minor compounds in methanol extract of the C. glaucum. It is concluded that aqueous and organic extracts of C. glaucum would be potential therapeutic agents and could be exploited on a pilot scale to treat human pathogenic diseases.

Salinity stress is one of the major plant growth-limiting factors in agriculture. It causes ionic imbalance, thus decrease the growth and yield attributes of crops especially wheat. Seedling stage is considered as one of the most sensitive stages under salinity stress. Survival of seeds at seedling stage can overcome the adverse impacts of salinity stress to some extent. Selection of salt tolerant varieties in seedling stage is considered as an effective strategy. Hence, current study was conducted to examine the seed germination responses of four wheat varieties under different levels of salinity. The wheat varieties such as ‘Rakhshan’, ‘Sirvan’, ‘Pishgam’ and ‘Heidari’ were grown and four salinity levels of 0, 4, 8 and 12 dS/m were applied under completely randomized design. The varieties such as ‘Sirvan’, ‘Rakhshan’ and ‘Heidari’ showed significant response for germination compared to ‘Pishgam’ at 12 dS/m salinity. Furthermore, the variety ‘Rakhshan’ showed significantly higher germination rate (20.3%), higher root length (33.4%) and higher shoot length (84.3%) than ‘Pishgam’, ‘Sirvan’ and ‘Sirvan’ respectively. However, contrasting results were obtained for dry weight of seedlings where 12.2% increase was observed in ‘Pishgam’ over ‘Rakhshan’ at 12 dS/m salinity that might be due to higher capability to uptake of Na and Cl ions. In conclusion, ‘Rakhshan’ wheat variety proved to be the most salinity tolerant as it grew better under saline soil conditions. More investigations at field level are recommended to declare ‘Rakhshan’ as salinity tolerant cultivar.

Fourier transform infrared spectroscopy (FTIR) spectroscopy detects functional groups such as vibrational bands like N-H, O-H, C-H, C = O (ester, amine, ketone, aldehyde), C = C, C = N (vibrational modes of a tetrapyrrole ring) and simply C = N. The FTIR of these bands is fundamental to the investigation of the effect of biochar (BC) treatment on structural changes in the chlorophyll molecules of both plants that were tested. For this, dried leaf of Spinacia oleracia (spinach) and Trigonella corniculata (fenugreek) were selected for FTIR spectral study of chlorophyll associated functional groups. The study's primary goal was to investigate the silent features of infrared (IR) spectra of dried leave samples. The data obtained from the current study also shows that leaf chlorophyll can mask or suppress other molecules' FITR bands, including proteins. In addition, the C = O bands with Mg and the C9 ketonic group of chlorophyll are observed as peaks at1600 (0%BC), 1650 (3%BC) and 1640, or near to1700 (5%BC) in spinach samples. In fenugreek, additional effects are observed in the FTIR spectra of chlorophyll at the major groups of C = C, C = O and C9 of the ketonic groups, and the vibrational bands are more evident at C-H and N-H of the tetrapyrrole ring. It is concluded that C-N bands are more visible in 5% BC treated spinach and fenugreek than in all other treatments. These types of spectra are useful in detecting changes or visibility of functional groups, which are very helpful in supporting biochemical data such as an increase in protein can be detected by more visibility of C-N bands in FTIR spectra.

Conservation agriculture-based sustainable intensification (CASI) technologies comprising zero-tillage with crop residue retention (>30%) on the soil surface, diversified cropping systems, and balanced nutrient management are recognized as operative and efficacious strategies to ensure food security in the parts of South Asia. The present investigation was a component of CASI technologies undertaken in the farmers' field of Malda (old alluvial Inceptisol) Coochbehar (recent alluvial Entisol) district, West Bengal (subtropical eastern India). This study was conducted to evaluate the short-term impact of contrasting tillage (zero and conventional) and cropping systems (rice-wheat and rice-maize) on total organic carbon (TOC) and its fractions, viz., labile pool-1 (LP1), labile pool-2 (LP2) and recalcitrant carbon (RC) fractions after 4-year trial of conservation agriculture (CA) in the old and recent alluvial soils. Soil samples were collected from three depths (0-5, 5-10, and 10-20 cm), and thus, our study was focused on two factors, viz., cropping system and tillage. Results pointed that TOC along with LP1, LP2, and RC fractions under rice-maize (RM) cropping system were significantly (p0.635; p RC > LP2 > LP1. The present investigation concluded that ZT under the RM system increases the turnover rates of C in both soil types but the amount of clay influences the stabilization/storage of C.

Rice (Oryza sativa L.) feeds to two-third of the global population by serving as staple food. It is the main export commodity of several countries; thus, contributes towards foreign exchange earnings. Unfortunately, average global rice yield is far below than its genetic potential. Low nitrogen (N) use efficiency (NUE) is among the major reasons for low average yield. Current study evaluated the impact of nitrogen fertilizer application methods (conventional and deep placement) on growth, yield-related traits, chlorophyll contents, photosynthesis rate, agronomic N-use efficiency (ANUE), partial factors productivity of applied N (PFP) and economic returns of two different transplanted rice varieties (Basmati-515 and Super-Basmati). Fertilizer application methods significantly affected allometry, yield-related traits, chlorophyll contents, photosynthesis rate, ANUE, PFP and economic returns. Deep placement of N-fertilizer (DPNF) observed better allometric traits, high chlorophyll contents, photosynthesis rate, ANUE, PFP, yield attributes and economic returns compared to conventional application of N-fertilizer (CANF). Similarly, Basmati-515 had better allometric and yield-related traits, chlorophyll contents, photosynthesis rate, ANUE, PFP and economic returns than Super-Basmati. Regarding interactions among N-fertilizer application methods and rice varieties, Basmati-515 with DPNF resulted in higher chlorophyll contents, photosynthesis rate, ANUE, PFP, allometric and yield related traits and economic returns than CANF. The lowest values of these traits were observed for Super-Basmati with no application of N-fertilizer. Both varieties had better yield and economic returns with DPNF compared to CANF. It is concluded that DPNF improved yield, ANUE and economic returns; therefore, should be opted to improve productivity of transplanted fine rice. Nonetheless, lower nitrogen doses need to be tested for DPNF to infer whether it could lower N use in rice crop.

ObjectivesAs a liquid organic fertilizer used in agriculture, digestate is rich in many nutrients (i.e. nitrogen, phosphorus, sulfur, calcium, potassium); their utilization may be however less efficient in soils poor in organic carbon (due to low carbon:nitrogen ratio). In order to solve the disadvantages, digestate enrichment with carbon-rich amendments biochar or humic acids (Humac) was tested.MethodsSoil variants amended with enriched digestate: digestate + biochar, digestate + Humac, and digestate + combined biochar and humic acids-were compared to control with untreated digestate in their effect on total soil carbon and nitrogen, microbial biomass carbon, soil respiration and soil enzymatic activities in a pot experiment. Yield of the test crop lettuce was also determined for all variants.ResultsSoil respiration was the most significantly increased property, positively affected by digestate + Humac. Both digestate + biochar and digestate + Humac significantly increased microbial biomass carbon. Significant negative effect of digestate + biochar (compared to the control digestate) on particular enzyme activities was alleviated by the addition of humic acids. No significant differences among the tested variants were found in the above-ground and root plant biomass.ConclusionsThe tested organic supplements improved the digestate effect on some determined soil properties. We deduced from the results (carbon:nitrogen ratio, microbial biomass and activity) that the assimilation of nutrients by plants increased; however, the most desired positive effect on the yield of crop biomass was not demonstrated. We assume that the digestate enrichment with organic amendments may be more beneficial in a long time-scaled trial.

Salinity stress is one of the major plant growth-limiting factors in agriculture. It causes ionic imbalance, thus decrease the growth and yield attributes of crops especially wheat. Seedling stage is considered as one of the most sensitive stages under salinity stress. Survival of seeds at seedling stage can overcome the adverse impacts of salinity stress to some extent. Selection of salt tolerant varieties in seedling stage is considered as an effective strategy. Hence, current study was conducted to examine the seed germination responses of four wheat varieties under different levels of salinity. The wheat varieties such as 'Rakhshan', 'Sirvan', 'Pishgam' and 'Heidari' were grown and four salinity levels of 0, 4, 8 and 12 dS/m were applied under completely randomized design. The varieties such as 'Sirvan', 'Rakhshan' and 'Heidari' showed significant response for germination compared to 'Pishgam' at 12 dS/m salinity. Furthermore, the variety 'Rakhshan' showed significantly higher germination rate (20.3%), higher root length (33.4%) and higher shoot length (84.3%) than 'Pishgam', 'Sirvan' and 'Sirvan' respectively. However, contrasting results were obtained for dry weight of seedlings where 12.2% increase was observed in 'Pishgam' over 'Rakhshan' at 12 dS/m salinity that might be due to higher capability to uptake of Na and Cl ions. In conclusion, 'Rakhshan' wheat variety proved to be the most salinity tolerant as it grew better under saline soil conditions. More investigations at field level are recommended to declare 'Rakhshan' as salinity tolerant cultivar.

Availability of good quality irrigation water is a big challenge in arid and semi arid regions of the world. Drought stress results in poor plant growth and low yield; however, the rhizobacteria, capable of producing 1-aminocyclopropane-1-carboxylate (ACC)-deaminase are likely to improve crop growth and productivity under drought stress. Similarly, biochar could also ameliorate the negative impacts of drought stress. Therefore, this pot experiment was conducted to evaluate the role of ACC-deaminase producing plant growth promoting rhizobacteria (PGPR) alone and in combinations with timber-waste biochar in improving maize growth under drought stress. The ACC-deaminase producing rhizobacteria, Pseudomonas aeruginosa, Enterobacter cloacae, Achromobacter xylosoxidans and Leclercia adecarboxylata were studied along with two rates (0.75 and 1.50% of the soil weight) of biochar under three moisture levels i.e., normal moisture, mild drought stress and severe drought stress. The E. cloacae in conjunction with higher rate of biochar produced a significant improvement i.e., up to 60, 73, 43, 69, 76 and 42% respectively, in grain yield plant-1, photosynthetic rate, stomatal conductance, chlorophyll a, total chlorophyll and carotenoids contents of maize as compared to the control under mild drought stress. Similarly, A. xylosoxidans with higher rate of biochar also enhanced grain yield plant-1, photosynthetic rate, stomatal conductance, chlorophyll a, total chlorophyll and carotenoids contents of maize up to 200, 213, 113, 152, 148 and 284%, respectively over control under severe drought stress. In conclusion, combination of ACC-deaminase containing PGPR, A. xylosoxidans and biochar (0.75%) proved an effective technique to improve maize growth and productivity under drought stress.