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Plastic film mulching (FM) became a general practice to enhance crop productivity and its net primary production (NPP), but it can increase greenhouse gas (GHG) emissions. The proper addition of organic amendments might effectively decrease the impact of FM on global warming. To evaluate the feasibility of biomass addition on decreasing this negative influence, cover crop biomass as a green manure was incorporated with different recycling levels (0-100% of aboveground biomass) under FM and no-mulching. The net global warming potential (GWP) which integrated with soil C stock change and GHG (N2O and CH4) fluxes with CO2-equivalent was evaluated during maize cultivation. Under the same biomass incorporation, FM significantly enhanced the grain productivity and NPP of maize by 22-61 and 18-58% over no-mulching, respectively. In contrast, FM also highly increased the respired C loss, which was 11-95% higher than NPP increase, over no-mulching. Irrespective with biomass recycling ratio and mulching system, negative NECB which indicates the decrease of soil C stock was observed, mainly due to big harvest removal. FM decreased more soil C stock by 57-158% over no-mulching, but its C stock was clearly increased with increasing biomass addition. FM significantly increased total N2O and CH4 fluxes by 4-61 and 140-600% over no-mulching, respectively. Soil C stock changes mainly decided net GWP scale, but N2O and CH4 fluxes negligibly influenced. As a result, FM highly increased net GWP over no-mulching, while this net GWP was clearly decreased with increasing biomass application. However, cover cropping, and its biomass recycling was not enough to compensate the negative impact of FM on global warming. Therefore, more biomass incorporation might be essential to compensate this negative effect of FM.

Saffron, also known as “the golden spice”, is one of the most expensive crops in the world. The expensiveness of saffron comes from its rarity, the tedious harvesting process, and its nutritional and medicinal value. Different countries of the world are making great economic growth due to saffron export. In India, it is cultivated mostly in regions of Kashmir owing to its climate and soil composition. The economic value generated by saffron export can be increased manyfold by studying the agronomical factors of saffron and developing a model for artificial cultivation of saffron in any season and anywhere by monitoring and controlling the conditions of its growth. This paper presents a detailed study of all the agronomical variables of saffron that have a direct or indirect impact on its growth. It was found that, out of all the agronomical variables, the important ones having an impact on growth include corm size, temperature, water availability, and minerals. It was also observed that the use of IoT for the sustainable cultivation of saffron in smart cities has been discussed only by very few research papers. An IoT-based framework has also been proposed, which can be used for controlling and monitoring all the important growth parameters of saffron for its cultivation.

Soil salinity and the use of saline groundwater are two major constraints in crop production, which covers a ~1.0 billion ha area of arid and semi-arid regions. The improved drainage function of soil can modify the salty growing environment for higher agricultural production. The present study evaluated the effectiveness of cut-soiler-constructed rice residue-filled preferential shallow subsurface drainage (PSSD) to improve the drainage function and its effect on the yield, quality and plant–water relations of mustard over 2019–2021. Cut-soiler-simulated drains were made in a semi-controlled lysimeter (2 × 2 × 3; L*W*H m) as the main plot treatment in a double replicated split–split experiment with two soil types (subplot) and three irrigation water salinities (4, 8 and 12 dS m−1) as the sub-sub-plot treatment. The drainage volume of variable salinity (EC), dependent on the total water input, was substantially higher in the rainy season (April to October), i.e., 16.6, 7.76 and 12.0% during 2018, 2019 and 2020, with 1.7, 0.32 and 0.77 kg salt removal per lysimeter, compared to the post-rainy season. The mustard seed, straw and biological yields were improved by 31.4, 14.41 and 18.08%, respectively, due to a positive effect on plant–water relations. The mustard seeds produced in the cut-soiler-treated plots recorded higher oil, crude fiber and protein contents and a lower erucic acid content. The increase in salt load, by higher-salinity irrigation water, was also efficiently managed by using cut-soiler PSSD. It was found that the saline irrigation water up to 12.0 dS m−1 can be used under such PSSD without any extra salt loading. The present study showed the potential of cut-soiler PSSD in root zone salinity management by improving drainage in salt-affected arid regions.

Two chickpea genotypes viz. Bhakar-2011 (desi) and Noor-2013 (kabuli) were sown in soil filled pots supplied with low (0.3 mg kg-1) and high (3 mg kg-1 soil) zinc (Zn) under control (70% water holding capacity and 25/20 °C day/night temperature), drought (35% water holding capacity) and heat (35/30 °C day/night temperature) stresses. Drought and heat stresses reduced rate of photosynthesis, photosystem II efficiency, plant growth and Zn uptake in chickpea. Low Zn supply exacerbated adverse effects of drought and heat stresses in chickpea, and caused reduction in plant biomass, carbon assimilation, antioxidant activity, impeded Zn uptake and enhanced oxidative damage. However, adequate Zn supply ameliorated adverse effect of drought and heat stresses in both chickpea types. The improvements were more in desi than kabuli type. Adequate Zn nutrition is crucial to augment growth of chickpea plants under high temperature and arid climatic conditions.

Medium-chain fatty acids (MCFA) such as caproic, heptanoic, and caprylic acids are monocarboxylic acids, which can be used as precursor molecules to synthesize biodiesel, bioplastics, antimicrobials, and corrosion inhibitors.

Flower opening in the early morning helps to avoid sterility of rice (Oryza sativa L.) caused by heat stress at anthesis. Although flower opening time (FOT) is under genetic control, it is also affected by weather, particularly by air temperature (Ta). However, the effects of Ta, solar radiation (Rs), and vapor-pressure deficit (VPD) on rice FOT are unclear, making it difficult to predict FOT. Therefore, we investigated the correlation of FOT with Ta, Rs, and VPD during various periods before anthesis under field conditions. By photographing spikelets at 10-min intervals, we determined the FOT of five cultivars. To evaluate the individual effects of cultivar, Ta, Rs, and VPD on FOT, we constructed general linear models (GLMs) and calculated mean Ta, R s, and VPD every 3 hr from 0000 to 1200. The GLMs revealed that the average Ta, Rs, and VPD between 0600 and 0900 significantly affected FOT (adjusted R 2 =0.399; P <0.001). The standardized partial regression coefficients of Ta and Rs were negative and those of VPD were positive, indicating that higher Ta, higher Rs, and lower VPD in the early morning result in earlier FOT. Moreover, multiple-regression analysis showed that the period affecting FOT the most, and the relative contributions of Ta, Rs, and VPD to FOT differ with the cultivar.

AbstractBiofuels from microalgae is now a hot issue of great potential. However, achieving high starch productivity with photoautotrophic microalgae is still challenging. A feasible approach to enhance the growth and target product of microalgae is to conduct mixotrophic cultivation. The appropriate acetate addition combined with CO2 supply as dual carbon sources (i.e., mixotrophic cultivation) could enhance the cell growth of some microalgae species, but the effect of acetate‐mediated mixotrophic culture mode on carbohydrate accumulation in microalgae remains unclear. Moreover, there is still lack of the information concerning how to increase the productivity of carbohydrates from microalgae under acetate‐amended mixotrophic cultivation and how to optimize the engineering strategies to achieve the goal. This study was undertaken to develop an optimal acetate‐contained mixotrophic cultivation system coupled with effective operation strategies to markedly improve the carbohydrate productivity of Chlorella sorokiniana NIES‐2168. The optimal carbohydrate productivity of 695 mg/L/d was obtained, which is the highest value ever reported. The monosaccharide in the accumulated carbohydrates is mainly glucose (i.e., 85–90%), which is very suitable for bio‐alcohols fermentation. Hence, by applying the optimal process developed in this study, C. sorokiniana NIES‐2168 has a high potential to serve as a feedstock for subsequent biofuels conversion.

Jerusalem artichoke is a low-requirement sugar crop containing cellulose and hemicellulose in the stalk and a high content of inulin in the tuber. However, the lignocellulosic component in Jerusalem artichoke stalk reduces the fermentability of the whole plant for efficient bioethanol production. In this study, Jerusalem artichoke stalk was pretreated sequentially with dilute acid and alkali, and then hydrolyzed enzymatically. During enzymatic hydrolysis, approximately 88 % of the glucan and xylan were converted to glucose and xylose, respectively. Batch and fed-batch simultaneous saccharification and fermentation of both pretreated stalk and tuber by Kluyveromyces marxianus CBS1555 were effectively performed, yielding 29.1 and 70.2 g/L ethanol, respectively. In fed-batch fermentation, ethanol productivity was 0.255 g ethanol per gram of dry Jerusalem artichoke biomass, or 0.361 g ethanol per gram of glucose, with a 0.924 g/L/h ethanol productivity. These results show that combining the tuber and the stalk hydrolysate is a useful strategy for whole biomass utilization in effective bioethanol fermentation from Jerusalem artichoke.