• Energy Research

Nitrogen (N) losses are prevalent under South East Asia’s due to high N fertilizer inputs, but low N fertilizer use efficiency. This leaves a large quantity of reactive N at risk of loss to the environment. Biochar has been found to reduce N losses across a variety of soil types, however, there is limited data available for semi-arid climates, particularly at a field-scale. Herein we present an exploration of the biological and chemical enhancement effects observed of a cotton stalk-based biochar on wheat growth and yield under arid field conditions. The biochar was treated with urea-N and biofertilizer (bio-power) in different treatment setups. The six experimental treatments included; (i) a full N dose “recommended for wheat crops in the region” (104 kg N ha−1) as a positive control; (ii) a half N dose (52 kg N ha−1); (iii) a half N dose + biofertilizer (4.94 kg ha−1) as a soil mixture; (iv) a half N dose + biofertilizer as a seed inoculation; (v) a full N dose as broadcast + biochar (5 t ha−1) inoculated with biofertilizer; and (vi) a full N dose loaded on biochar + biofertilizer applied as a soil mixture. The half dose N application or biofertilizer addition as soil mix/seed inoculated/biochar inoculation with biofertilizer caused reduced wheat growth and yield compared to the control (conventional N fertilization). However, co-application of chemically enhanced biochar (loaded with a full N dose) and biofertilizer as soil mixture significantly increased the crop growth rate (CGR) and leaf area index (LAI). A significantly higher crop growth and canopy development led to a higher light interception and radiation use efficiency (RUE) for total dry matter (TDM) and grain yield (11% greater than control) production compared to the control. A greater grain yield, observed for the full N dose loaded on biochar + biofertilizer applied as a soil mixture, is attributed to prolonged N availability as indicated by greater plant and soil N content at harvest and different crop growth stages, respectively. The present study has improved our understanding of how the application of nitrogen loaded biochar and biofertilizer as soil mixtures can synergize to positively affect wheat growth and soil-nitrogen retention under arid environmental conditions.

Cladosporium spp. are known to be mycoparasites and inhibit phytopathogenic fungi. However, so far, little information is available on the impact of Cladosporium spp. on powdery mildews. Based on the morphological characteristics and molecular analysis, C. sphaerospermum was identified as a mycoparasite on the wheat powdery mildew fungus Blumeria graminis f. sp. tritici (Bgt), recently named B. graminis s. str. C. sphaerospermum was capable of preventing colony formation and conidial distribution of Bgt. The biomasses of Bgt notably decreased by 1.3, 2.2, 3.6, and 3.8 times at 2, 4, 6, and 8 days postinoculation (dpi), respectively. In addition, biomasses of C. sphaerospermum at 2, 4, 6, and 8 dpi significantly increased to 5.6, 13.9, 18.2, and 67.3 times, respectively. In vitro, C. sphaerospermum exudates significantly impaired appressorial formation of Bgt. Thus, C. sphaerospermum acts as a potential biological control agent by suppressing the formation, distribution, and development of Bgt conidia and is a viable alternative for managing the wheat powdery mildew. These results suggest that C. sphaerospermum is an antagonistic parasite of the wheat powdery mildew fungus and, hence, provide new knowledge about the biological control of phytopathogenic fungi.

Abstract Crop production is greatly impacted by growing season duration, which is driven by prevailing environmental conditions (mainly temperature) and agronomic management practices (particularly changes in cultivars and shifts in sowing dates). It is imperative to evaluate the impact of climate change and crop husbandry practices on phenology to devise future management strategies to prepare for climate change. Historical changes in spring and autumn maize phenology were observed in Punjab, Pakistan during 1980–2014. Sowing (S) of spring maize was earlier by an average of 4.6 days decade−1, while autumn maize ‘S’ and emergence (E) were delayed on average 3.0and 1.9 days decade−1. Observed anthesis (A) plus maturity (M) dates were earlier by 7.1 and 9.2 days decade−1 and 2.8 and 4.4 days decade−1for spring and autumn maize, respectively. Similarly, S-A, S-M and A-Mphases were shortened on average by 2.4, 4.6 and 1.9 days decade−1 and 5.5, 7.8 and 2.2 days decade−1 for spring and autumn maize, respectively. The variability in phenological phases of spring and autumn maize had significant correlation,with the increase in temperature during 1980–2014. Employing the CSM-CERES-Maize model using standard hybrid for all locations and years illustrated that model-predicted phenology has accelerated with climate change more than infield-observed phenology. These findings suggest that earlier late sowing and shifts of cultivars requiring high total growing degree day during 1980–2014, have partially mitigated the negative impact of climate change on phenology of both spring and autumn grown maize.

Nitrogen (N) fertilizer is an important yield limiting factor for sunflower production. The correlation between yield components and growth parameters of three sunflower hybrids (Hysun-33, Hysun-38, Pioneer-64A93) were studied with five N rates (0, 60, 120, 180, 240 kg ha(-1)) at three different experimental sites during the two consecutive growing seasons 2008 and 2009. The results revealed that total dry matter (TDM) production and grain yield were positively and linearly associated with leaf area index (LAI), leaf area duration (LAD), and crop growth rate (CGR) at all three sites of the experiments. The significant association of yield with growth components indicated that the humid climate was most suitable for sunflower production. Furthermore, the association of these components can be successfully used to predict the grain yield under diverse climatic conditions. The application of N at increased rate of 180 kg ha(-1) resulted in maximum yield as compared to standard rate (120 kg ha(-1)) at all the experimental sites. In this way, N application rate was significantly correlated with growth and development of sunflower under a variety of climatic conditions. Keeping in view such relationship, the N dose can be optimized for sunflower crop in a particular region to maximize the productivity. Multilocation trails help to predict the input rates precisely while taking climatic variations into account also. In the long run, results of this study provides basis for sustainable sunflower production under changing climate.

La température moyenne pourrait atteindre 2,0-4,5 °C dans le monde d'ici la fin de ce siècle. En plus de cela, une prédiction a été faite que l'augmentation de la température minimale de nuit sera à un rythme plus rapide par rapport à la température maximale de jour. La hausse des températures affecte non seulement le processus de croissance des cultures, mais entraîne également des changements directs dans d'autres facteurs environnementaux et a un effet indirect sur le rendement et la qualité du riz, de sorte qu'au stade actuel, elle a attiré l'attention du public. Les races, y compris par la sélection et la biotechnologie pour améliorer la tolérance à la température élevée du riz, aident à atténuer les effets négatifs de la température élevée, cependant, les progrès dans ce domaine ont été lents. En adoptant différentes méthodes comme le semis, la gestion de l'eau et des nutriments peut également, dans une certaine mesure, atténuer les effets de la température élevée sur les performances du riz, mais dans la plupart des cas, ces techniques sont influencées par de nombreux facteurs, tels que la rotation des cultures, l'irrigation et d'autres contraintes telles que leurs applications sont difficiles à appliquer sur de grandes surfaces. Par conséquent, ce chapitre aborde (1) la réduction empirique du rendement du riz (2) met en évidence les principaux mécanismes importants qui influencent les principaux attributs de qualité des céréales soumises à un stress à haute température (3) induisant une résistance au stress et adoptant des stratégies d'atténuation pour une haute performance du riz. La temperatura media podría aumentar hasta un rango de 2,0-4,5 °C en todo el mundo a finales de este siglo. Aparte de esto, se ha hecho una predicción de que el aumento de la temperatura mínima nocturna será a un ritmo más rápido en comparación con la temperatura máxima diurna. El aumento de las temperaturas no solo afecta el proceso de crecimiento de los cultivos, sino que también conduce a cambios directos en otros factores ambientales y plantea un efecto indirecto en el rendimiento y la calidad del arroz, por lo que en la etapa actual, despertó la atención del público. Las razas, incluso a través de la cría y la biotecnología para mejorar la tolerancia al arroz a altas temperaturas, ayudan a mitigar los efectos negativos de las altas temperaturas, sin embargo, el progreso en esta área ha sido lento. Al adoptar diferentes métodos como la siembra, el manejo del agua y los nutrientes también puede mitigar en cierta medida los efectos de la alta temperatura en el rendimiento del arroz, pero en la mayoría de los casos, estas técnicas están influenciadas por muchos factores, como la rotación de cultivos, el riego y otras restricciones, ya que sus aplicaciones son difíciles de aplicar a grandes áreas. Por lo tanto, este capítulo aborda (1) la reducción empírica del rendimiento del arroz (2) destaca los mecanismos clave significativos que influyen en los principales atributos de calidad del grano bajo estrés por alta temperatura (3) induciendo resistencia al estrés y adoptando estrategias de mitigación para un alto rendimiento del arroz. The mean temperature might rise up to range of 2.0–4.5 °C worldwide by the end of this century. Beside from this, a prediction has been made that rise in minimum night temperature will be at a quicker rate as compare to the maximum day temperature. Rising temperatures not only affect the crop growth process, but also lead to direct changes in other environmental factors and pose indirect effect on yield and quality of rice has been observed, so at the present stage, it aroused public attention. Breeds, including through breeding and biotechnology to improve high temperature tolerance of rice help to mitigate the negative effects of high temperature, however, progress in this area have been slow. By adopting different methods like sowing, water and nutrient management can also to some extent mitigate the effects of high temperature on rice performance, but in most cases, these techniques are influenced by many factors, such as crop rotation, irrigation and other constraints like their applications are hard to applied to large area. Therefore, this chapter addresses (1) empirical reduction of rice yield (2) highlights the key significant mechanisms that influence main grain quality attributes under high temperature stress (3) inducing stress resistance and adopting mitigation strategies for high performance of rice. قد يرتفع متوسط درجة الحرارة إلى نطاق 2.0-4.5 درجة مئوية في جميع أنحاء العالم بحلول نهاية هذا القرن. إلى جانب ذلك، تم التنبؤ بأن الارتفاع في الحد الأدنى لدرجة الحرارة الليلية سيكون بمعدل أسرع بالمقارنة مع الحد الأقصى لدرجة الحرارة النهارية. لا يؤثر ارتفاع درجات الحرارة على عملية نمو المحاصيل فحسب، بل يؤدي أيضًا إلى تغييرات مباشرة في العوامل البيئية الأخرى ويشكل تأثيرًا غير مباشر على محصول الأرز وجودته، لذلك في المرحلة الحالية، أثار اهتمام الجمهور. تساعد السلالات، بما في ذلك من خلال التكاثر والتكنولوجيا الحيوية لتحسين تحمل درجات الحرارة العالية للأرز، على التخفيف من الآثار السلبية لارتفاع درجة الحرارة، ومع ذلك، كان التقدم في هذا المجال بطيئًا. من خلال اعتماد طرق مختلفة مثل البذر، يمكن للمياه وإدارة المغذيات أيضًا إلى حد ما التخفيف من آثار ارتفاع درجة الحرارة على أداء الأرز، ولكن في معظم الحالات، تتأثر هذه التقنيات بالعديد من العوامل، مثل دوران المحاصيل والري والقيود الأخرى مثل تطبيقاتها التي يصعب تطبيقها على مساحة كبيرة. لذلك، يتناول هذا الفصل (1) التخفيض التجريبي لمحصول الأرز (2) يسلط الضوء على الآليات المهمة الرئيسية التي تؤثر على سمات جودة الحبوب الرئيسية تحت ضغط درجة الحرارة العالية (3) تحفيز مقاومة الإجهاد واعتماد استراتيجيات التخفيف للأداء العالي للأرز.

Solar radiation (SR) is essential for yield improvement in lentil, which is a crop of marginal environments. Herein, experiments were conducted over 2 years under a semi-arid environment to study the radiation interception (RI), efficiency, growth, and development of three lentil genotypes (Punjab Masoor-2009 (PM-2009), NIAB Masoor-2006 (NM-2006), and NIAB Masoor-2002 (NM-2002)) in relation to three nitrogen rates (13, 19, and 25 kg ha-1). Seasonal dynamics of intercepted photoactive radiation (IPAR) and cumulated photosynthetic photon flux density were highly associated with seasonal dynamics of leaf area index (LAI), with a high value of R2 (0.93 and 0.89) across all nitrogen rates and genotypes in both years. Nitrogen application promoted growth, and maximum LAI (3.97 and 3.57) and RI (324 and 301 MJ m-2) were attained for the first and second years of study, respectively. Biomass and yield were positively associated with IPAR. Variation in radiation absorption (RA) among genotypes was due to different patterns of LAI development. In both years, yield (23% and 25%) and radiation use efficiency (RUE) for grain yield (0.44 and 0.37 g MJ-1) were respectively higher for PM-2009 than for the other genotypes. Genotype PM-2009 had 15 days shorter crop cycle than others while 14% higher GDDs accumulated in the first year compared with the second due to the higher temperature. High nitrogen (25 kg ha-1) application resulted in higher dry matter (DM), and grain yield (GY), while RUE and PAR were not statistically different under 19 kg N ha-1 application across years. Genotypes PM-2009 and NM-2006 may perform reasonably well under arid to semi-arid regions at farmer field. These findings may assist researchers and crop modelers to optimize the lentil ideotype for efficient light utilization.

Cover crops (CCs) have been increasingly cultivated to boost soil quality, crop yield, and minimize environmental degradation compared with no cover crops (NCCs). There is no consensus of CCs under different climatic conditions on soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and soil microbial biomass carbon and nitrogen ratio (SMBC/SMBN) are yet documented. Thus, a global meta-analysis of 40 currently available literature was carried out to elucidate the effect of CCs on SMBC and SMBN, and its ratio for cash and cover cropping systems was conducted. Our findings demonstrated that CCs increased SMBC, SMBN, and SMBC/SMBN ratios by 39, 51, and 20%, respectively, as compared to NCCs. The categorical meta-analyzes showed that the mixture of legume and nonlegume CCs decreased the SMBC, SMBN, and SMBC/SMBN ratios relative to the sole legume or nonlegume CCs. Nonlegume CCs enhanced the SMBC, SMBN, and SMBC/SMBN ratio compared to legume CCs. When CCs residues were incorporated into the soil or surface mulched, the SMBC and SMBN increased compared to the removal of residues. The effect of CCs on the SMBN and SMBC/SMBN ratio was higher in medium-textured soils compared to coarser or fine-textured soils, but coarser-textured soils have a higher SMBC. The effect of CCs on SMBN and SMBC/SMBN ratio was prominent on medium-textured soils having soil organic carbon (SOC) in the range of 10-20 mg g-1, pH > 6.5, and total nitrogen (TN) in the range of 1-2%. It was concluded that CCs enhanced SMBC, SMBN, and its ratio compared to NCCs. The response, however, varied depending on the soil properties and climatic region. Cover crops can boost the biological soil's health by increasing the microbial population's abundance compared to NCCs.

Jute (Corchorus capsularis L.) is the most commonly used natural fiber as reinforcement in green composites and, due to its huge biomass, deep rooting system, and metal tolerance in stressed environments, it is an excellent candidate for the phytoremediation of different heavy metals. Therefore, the present study was carried out to examine the growth, antioxidant capacity, gaseous exchange attributes, and phytoremediation potential of C. capsularis grown at different concentrations of Cu (0, 100, 200, 300, and 400 mg kg-1) in a glass house environment. The results illustrate that C. capsularis can tolerate Cu concentrations of up to 300 mg kg-1 without significant decreases in growth or biomass, but further increases in Cu concentration (i.e., 400 mg kg-1) lead to significant reductions in plant growth and biomass. The photosynthetic pigments and gaseous exchange attributes in the leaves of C. capsularis decreased as the Cu concentration in the soil increased. Furthermore, high concentrations of Cu in the soil caused lipid peroxidation by increasing the malondialdehyde content in the leaves. This implies that elevated Cu levels cause oxidative damage in C. capsularis. Antioxidants, such as superoxidase dismutase and peroxidase, come into play to scavenge the reactive oxygen species which are generated as a result of oxidative stress. In the present study, the concentrations of Cu in different parts of the plant (the roots, leaves, stem core, and fibers) were also investigated at four different stages of the life cycle of C. capsularis, i.e., 30, 60, 90, and 120 days after sowing (DAS). The results of this investigation reveal that, in the earlier stages of the growth, Cu was highly accumulated in the belowground parts of the plant while little was transported to the aboveground parts. Contrastingly, at a fully mature stage of the growth (120 DAS), it was observed that the majority of Cu was transported to the aboveground parts of the plant and very little accumulated in the belowground parts. The results also show a progressive increase in Cu uptake in response to increasing Cu concentrations in the soil, suggesting that C. capsularis is a potential bio-resource for the phytoremediation of Cu in Cu-contaminated soil.