Observed increasing water constraint on vegetation growth over the last three decades

Despite the growing interest in predicting global and regional trends in vegetation productivity in response to a changing climate, changes in water constraint on vegetation productivity (i.e., water limitations on vegetation growth) remain poorly understood. Here we conduct a comprehensive evaluation of changes in water constraint on vegetation growth in the extratropical Northern Hemisphere between 1982 and 2015. We document a significant increase in vegetation water constraint over this period. Remarkably divergent trends were found with vegetation water deficit areas significantly expanding, and water surplus areas significantly shrinking. The increase in water constraints associated with water deficit was also consistent with a decreasing response time to water scarcity, suggesting a stronger susceptibility of vegetation to drought. We also observed shortened water surplus period for water surplus areas, suggesting a shortened exposure to water surplus associated with humid conditions. These observed changes were found to be attributable to trends in temperature, solar radiation, precipitation, and atmospheric CO2. Our findings highlight the need for a more explicit consideration of the influence of water constraints on regional and global vegetation under a warming climate.

STUDIES ON IMPACT OF IRRIGATION AND WATER CONSERVATION PRACTICES ON THE GROWTH AND YIELD OF DIRECT SOWN RICE UNDER WATER CONSTRAINT SITUATION

An experiment was conducted to study the agronomic practices for growth and yield maximization of direct sown rice under water constraint situation. The main plot treatments comprised of three levels of irrigation viz., Conventional irrigation (M1 ), tensiometer based irrigation (M2 ) and deficit irrigation (M3 ) respectively and were tested with different water conservation practices viz., soil application of water saving crystals (WSC) @ 5 kg ha-1 (S1 ), foliar application of drought shield @ 3 liters ha-1(S2 ), soil application of humic granules @ 2.5 kg ha-1 (S3 ) and soil application of FYM @ 12.5 t ha-1 (S4 ). Interaction between different levels of irrigation and water conservation practices were significantly influenced. Tensiometer based irrigation along with soil application of humic granules @ 2.5 kg ha-1 (M2 S3 ) recorded the higher growth and yield parameters in direct sown rice.

Yield maximization of direct sown rice (Oryza sativa l.) under water constraint situation

More efficient water management practices need to be adopted for better sustainable rice production grown under traditional areas due to increased water scarcity. Among the different water management practices, efficient new generation water-saving chemicals and organic products were used to conserve water under field condition. An experiment was conducted to evaluate the yield maximization in direct sown CO51 rice (Oryza sativa L.) under water constraint situation. The main plot treatments comprised of three levels of irrigation viz., Conventional irrigation (M1), Tensiometer based irrigation (M2) and Deficit irrigation (M3), respectively and were tested with four different water conservation practices in sub-plots viz., soil application of water-saving crystals (WSC) @ 5 kg ha-1 (S1), foliar application of drought shield @ 3 litres ha-1 (S2 ), soil application of humic granules @ 2.5 kg ha-1 (S3) and soil application of FYM @ 12.5 t ha-1 (S4). Experimental results indicated that Tensiometer based irrigation with soil application humic granules @ 2.5 kg ha-1 M2S3) recorded higher number of panicles m-2 (411) and number of filled grains panicle-1 (108.16) in direct-sown rice. However, M2S3 recorded significantly maximum grain yield (6352 kg ha-1) and minimum (3940 kg ha-1) in (M3S4) deficit irrigation applied with FYM @12.5 t ha-1 in the year 2018 Sornavari season, respectively. Thus the Tensiometer based irrigation with soil application of humic granules @ 2.5 kg ha-1 can be a feasible approach for increasing grain yield and conserve water in north eastern region of Tamil Nadu, by promoting water use efficiency method in direct rice cultivation areas.

New insights into Viticulture, Enology and Vitivinicultural Economy: Ciência e Técnica Vitivinícola 2021

New insights into Viticulture, Enology and Vitivinicultural Economy arise from the fourteen articles published by the Ciência e Técnica Vitivinícola in 2021. Research carried out by several international teams covered a wide range of topics that seek to respond to current main challenges: chemical, morphological and anatomical features of the grapevine cultivars explored to withstand biotic and abiotic stresses; seaweed foliar application to grapevines as an innovative and integrated vineyard management technique; nutritional management of grapevine cultivars under cold climate conditions and under water constraint scenarios; viability and cost-effectiveness of photovoltaic solar energy for wineries; viticultural technologies and the food safety of wine; characterization of grapes and methods for juice production; chemical composition of grape seeds; development of analytical and sensory methodologies; portrait of the wine spirits sector in Portugal and its recent evolution.

Influence of water scarcity on macronutrients contents in young leaves of wine grape cultivars

This study aimed to determine the variability of plant nutrition content in two-year old local and well-known wine grape cultivars under different water constraint scenarios. Own rooted and potted eight grapevine cultivars (cv. ‘Adakarası’, ‘Papazkarası’, ‘Karasakız’, ‘Karalahana’, ‘Yapıncak’, ‘Vasilaki’, ‘Cabernet Sauvignon’ and ‘Sauvignon Blanc’) were subjected to five irrigation treatments (100% daily irrigation of available water capacity (AWC), 75% irrigation of AWC, 50% irrigation of AWC, 25% irrigation of AWC, and no irrigation for 0% treatment) for two consecutive years during vegetative growth (May – late September). An increase in nitrogen, potassium and magnesium contents in leaf tissues with decreasing water amount was observed. Similar effect was found for phosphorus and calcium contents. The sulfur concentration in leaf tissues remained almost unchanged. In addition, the variability of genetic potential influenced the nutrient intake of the studied cultivars. The ability of grapevine cultivars to cope with the water deficit of the cultivars should definitely be assessed in adaptation strategies developed to make viticulture sustainable under the effects of the climate crisis.

Effet de quatre types de fertilisants sur la croissance et la productivité de deux génotypes de maïs (Zea mays L.) en cas d’un semis tardif à Korhogo au Centre-Nord de la Côte d’Ivoire

Face à un appauvrissement des sols et une irrégularité des pluies du fait du changement climatique, une étude a été entreprise sur la culture du maïs au Centre-Nord de la Côte d’Ivoire. Elle avait pour objectif d’évaluer l’influence de quatre types de fumures sur le potentiel agronomique de deux génotypes de maïs (Zea mays L.) en cas de contrainte hydrique de fin de cycle et d’infertilité des sols. Le dispositif expérimental a été un split-plot, dont le premier facteur a été les fertilisants et le second, la variété. Les résultats ont montré que les fumures ont influencé les durées des phases végétative et reproductive en plus du rendement. Les fumures fiente de poulet et déjection de boeuf ont permis d’obtenir un rendement qui est égal à six fois celui obtenu avec le témoin de la variété à grain noir malgré la contrainte hydrique. Aussi, la fumure fiente de poulet a eu une tendance à réduire le cycle de culture et favoriser une meilleure croissance et un bon développement des plantes. L’utilisation de ces fumures en culture du maïs, pourrait constituer une alternative aux conséquences drastiques du changement climatique. © 2020 International Formulae Group. All rights reserved. Mots clés: Fertilisants, maïs (Zea mays L.), potentiel agronomique, rendement, contrainte hydrique English Title: Effect of four types of fertilizers on the growth and productivity of two maize genotypes (Zea mays L.) in the event of late planting in Korhogo in North-Central Côte d'Ivoire English Abstract Faced with soil depletion and irregular rains due to climate change, a study was undertaken on maize cultivation in North-Central Côte d'Ivoire. Its objective was to assess the influence of four types of manure on the agronomic potential of two maize genotypes (Zea mays L.) in cases of water stress and soil infertility. The experimental set-up was a split-plot, the first five-level factor being fertilizers and the second two-level factor being variety. Observations were made on phenology, growth parameters and yield. The results showed that manure influenced vegetative and reproductive time, growth parameters and yield. In terms of yield, chicken droppings and beef droppings were the most effective. They yielded six times the yield obtained with the black-grain variety control despite the water constraint at the end of the cycle. Also, chicken manure has had a tendency to reduce the growing cycle and promote better growth and plant development. The use of these manure in maize cultivation could be an alternative to the drastic consequences of climate change. © 2020 International Formulae Group. All rights reserved. Keywords: Fertilizers, corn (Zea mays L.), agronomic potential, yield, water constraint

Water Constraint is Limiting Global Gross Primary Productivity

<p> </p><p>We use a light use efficiency model (LUE)  to describe gross primary productivity (GPP) from 1982 to 2016 using the GIMMS-3g FPAR record and NASA MERRA-2 reanalysis, and explore how GPP trends and anomalies can be explained using annual changes in temperature and hydrology. The GPP model uses optimum LUE (LUE<sub>opt</sub>) inferred from the global FLUXNET network and extrapolated using solar induced chlorophyll fluorescence observations. We find that increasing trends in GPP at mid to high latitudes over the 35-year study period are due to reduced cold temperature of plant growth constraints. Our results suggest a persistent and increasing negative carbon-climate feedback at mid to high latitudes. We also find an increasing atmospheric vapor pressure deficit trends over the tropics, which represents an emerging positive climate feedback that results in a negative trend in GPP after the early 2000s. We expect that further warming, increasing water constraints, and disturbance events will significantly reduce global ecosystem productivity.</p>