Adequate Water Availability Research Articles

Central China as LGM plant refugia: Insights from biome reconstruction for palaeoclimate information

The demonstration of survival of forest stands in relatively stable refugia during cold glacial stages has offered an increased understanding of the response of vegetation to climate change, but also provides insight into considerations for the conversation of biodiversity hotspots. However, refugia studies in China remain in question due to the lack of plant macrofossils, especially those of endemic and relict species. Palynology, while more broad brush, provides a method for exploring whether refugia occur, and can provide some details of palaeovegetation composition and temporal dynamics. Here, three pollen records derived from subalpine wetlands in central China, spanning the Last Glacial Maximum (LGM), have been coupled with biome and mean annual precipitation (MAP) reconstructions to identify the presence of trees that endured cold climate. The results indicated that some forest, including temperate deciduous broadleaf forest and cool mixed forest, survived the LGM at the three locations, and was thus at odds with the hypothesis that forests were replaced by herbs and grasses in central China at that time. Refugia favored by protection from cold air drainage and the availability of adequate water can explain the survival of the trees during otherwise harsh episodes. Our findings are consistent with other records from central China that argue for tree dominated refugia during the LGM.

Effects of water stress on nutrients and enzyme activity in rhizosphere soils of greenhouse grape.

In grape cultivation, incorrect water regulation will lead to significant water wastage, which in turn will change soil structure and disrupt soil nutrient cycling processes. This study aimed to investigate the effects of different water regulation treatments [by setting moderate water stress (W1), mild water stress (W2), and adequate water availability (CK)] on soil physical-chemical properties and enzyme activity in greenhouse grape during the growing season. The result showed that the W2 treatment had a negative impact on the build-up of dissolved organic carbon (DOC), nitrate nitrogen (NO3-N), and available phosphorus (AP). Throughout the reproductive period, the W1 and W2 treatments decreased the soil's microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents, and MBC was more vulnerable to water stress. During the growth period, the trends of urease, catalase, and sucrase activities in different soil depth were ranked as 10-20 cm > 0-10 cm > 20-40 cm. The urease activity in 0-10 cm soil was suppressed by both W1 and W2 treatments, while the invertase activity in various soil layers under W1 treatment differed substantially. The W1 treatment also reduced the catalase activity in the 20-40 cm soil layer in the grape growth season. These findings suggested that W2 treatment can conserve water and enhance microbial ecology of greenhouse grape soils. Therefore, W2 treatment was the most effective water regulation measure for local greenhouse grape cultivation.

Soil water availability modulates the response of grapevine leaf gas exchange and PSII traits to a simulated heat wave

Background and aimsA better understanding of plant carbon assimilation, water status and photosystem performance responses to combined heat and drought stress would help to optimize grapevine management under such limiting conditions.MethodsGas exchange and chlorophyll fluorescence parameters were measured in potted grapevines, cv Sauvignon Blanc, before, during and after simulated six-day heat (Tmax = 40 °C) wave using heated well-watered (HW), heated drought-stressed (HD), non-heated well-watered (CW) and non-heated dry (CD) vines.ResultsPhotosynthesis and stomatal conductance in HW vines increased during the morning and dropped in the afternoon with respect to CW vines. Daily plant transpiration in HW almost doubled that of CW vines. When grapevines were already exposed to drought, the effects of the heat wave were negligible, with HD plants showing similar leaf photosynthesis and transpiration to their CD counterparts. Heat, but not drought stress, decreased the maximum (Fv/Fm) and effective photochemical quantum yield of PSII (φPSII), and also affected the use of absorbed energy. HW plants dissipated more radiative energy as heat, a protective mechanism of the photosystem, while HD vines increased the energy dissipated by non-regulated non-photochemical pathways, which might lead to photoinhibition damages. The different behavior could be due to the enhanced transpiration rate and consequent decrease in leaf temperature in HW as compared to HD vines. After the heat wave, only HW vines recovered the afternoon values of photosynthesis, stomatal conductance and φPSII to similar levels as those in CW vines.ConclusionDrought had a more significant effect than heat stress on photosynthesis, stomatal conductance and transpiration. The combined heat and drought stress, however, increased the proportion of energy lost by the leaves through harmful non-regulated dissipative pathways. With adequate soil water availability, grapevines withstood the heat wave period through an increase in leaf transpiration, which decreased leaf temperature and protected the PSII from heat damage.

Analisis Hubungan Antar Parameter Air Bersih di Sekitar Rencana Pembangunan Pasar Agro Kabupaten Bojonegoro

Markets are places that facilitate buying and selling activities and are visited by many people, it making them vulnerable to the spread of a disease that can come from virus-carrying animals or inadequate sanitation. A healthy market should have good sanitation, such as adequate availability of water as sanitary higiene with adequate quality. Water used for sanitary hygiene purposes must be protected from pollutant sources and safe from contamination, and meet quality standards according to Regulation of the Minister of Health No. 32 of 2017. Therefore, to determine the quality of water that will be used to meet the sanitation needs of the market, this study measured the quality of clean water directly at three points around the location of the “Pasar Agro” development plan. Water quality measurements are carried out using methods according to the Indonesian National Standard according to each parameter to be measured. Based on the results of the measurements carried out, there are two chemical parameters that have not met, namely manganese and detergent parameters, as well as biological parameters in the form of total coliform. Correlation testing was carried out using Minitab 17 software on water chemistry parameters to determine the relationship between parameters, and it was found that there were only a few parameters that were related to each other.

Availability of clean water and discharge reliable for housing taman argo subur cisoka, tangerang district

The problem of water availability is an important issue in the development of a residential area, because the availability of water resources is the supporting capacity for the development of a residential area. Adequate water availability for now and predictions of future water availability are very important to know for ensuring an area that is feasible for development. The purpose of this study is to determine the amount of water availability through the method of calculating the water balance and calculating the mainstay discharge to find out whether the water needs are fulfilled or not. Household water consumption is one of the biggest contributors to the water crisis in residential areas. For this reason, it is necessary to have information that has high accuracy regarding the existence of water sources and the amount of water reserves owned by a location. The water balance is one way to determine the availability of water in an area so that it can be calculated whether the location will experience a water crisis or not. Calculation of water balance using the FJ Mock method can provide the information needed whether an area has a surplus of water or not and can be used to calculate the mainstay discharge which is useful for distributing water to residents. Making reservoirs or tendons is an alternative to overcome the occurrence of a water crisis when the dry season comes because often residential areas experience water shortage problems. For this reason, a calculation is made regarding the amount of water debit produced by the water reservoir made by the manager and the amount of surplus water is based on the monthly average method. The results of the calculation of the FJ Mock discharge can be seen that the resulting maximum discharge is 0.504 m3/second and the minimum discharge is 0.069 m3 / sec. The results of the reliable discharge calculation show that the water discharge is still acceptable or meets the criteria because even though in August the water discharge that was achieved was only 0.069 m3/sec, this amount still meets the requirements at a reliability value of 99% and at an error value of 1%. These results provide evidence that the discharge generated by the two residential tendons of Taman Argo Subur still meets the requirements.

A Study to Assess the Effectiveness of Planned Teaching Program on Awareness Regarding Environmental Sanitation among the ASHA (Accredited Social Health Activist) Workers Working in Selected Rural Community Area

Background: Water, sanitation and waste management are important driving forces for community health in India. A clean environment, open defecation free areas, personal hygiene practices among the individuals, proper solid and liquid waste management, and availability of adequate safe drinking water determine the health of individuals as well as the community. Aim and Objective: A study was planned to assess awareness regarding environmental sanitation among the ASHA (Accredited Social Health Activist) workers working in selected rural community area. Material and method: A per-experimental pre-test post-test design was used to assess the effectiveness of planned teaching program on the awareness of 30 ASHA (Accredited Social Health Activist) Workers selected by non-probability convenient sampling. Result: The analysis and interpretation revealed that the effectiveness of planned teaching program as the post-test awareness score of the ASHA workers regarding environmental sanitation was significantly higher than the pre-test awareness score. Conclusion: Our result indicates that the planned teaching program was an effective tool for improving the awareness regarding environmental sanitation among ASHA (Accredited Social Health Activist) Workers.

Radiation and temperature dominate the spatiotemporal variability in resilience of subtropical evergreen forests in China

Forest resilience is crucial to the mitigation of climate change, due to the enormous potential of forests to reduce atmospheric carbon dioxide concentrations and the possible conversion of forests from net carbon sinks into carbon sources following external disturbances. Subtropical forests are suffering the highest rates of forest change, but how they are evolving in response to climate change is little known. In this study, we estimated the spatial pattern and temporal trend of the resilience of subtropical evergreen forests in China by applying the lag-one autocorrelation (AC1) method to satellite kernel normalized difference vegetation index (kNDVI) data over the past two decades and identified the influential environmental factors that affect the ecosystem resilience by developing random forest (RF) regression models. The computed long-term AC1 based on kNDVI for the 2001–2020 period depicts considerable spatial variability in the resilience of the subtropical evergreen forests in China, with lower resilience at lower latitudes. The RF regression analysis suggests that the spatial variability in the forest resilience can be re-established by forest and climatic variables, and is largely affected by climate, with the three most influential variables being solar radiation (SR, %incMSE = 20.7 ± 1.8%), vapor pressure deficit (VPD, %incMSE = 13.8 ± 0.2%) and minimum temperature (Tmin, %incMSE = 13.3 ± 1.2%). Higher forest resilience is more likely to be located in areas with less radiation stress, adequate water availability, and less warming. Trend analysis shows a declining trend for the resilience of subtropical evergreen forests in China since the 2000s but an increasing forest resilience in the last decade, which is mainly dominated by temperature changes, including average and minimum temperatures. Considering the expected warming-dominated period in times of rapid climatic change, we suggest potential critical responses for subtropical forest productivity to the disturbances should be of greater concern in the future.

Pythium spp. – rosnący problem w uprawie ogórka pod osłonami

In 2022 and 2023, a record number of cucumber samples came to the Plant Diseases Clinic in Institute of Plant Protection – National Research Institute in Poznan. The dominant problem (more than 90% of the samples) was the sudden wilting of healthy-looking plants, despite adequate water availability. The yield decreased drastically, and the plants in the entire rows dried up and died prematurely. Until 2019, similar symptoms appeared sporadically on cucumbers delivered to the Clinic. On the basis of microscopic observation, confirmed by isolation on artificial substrates from fragments of infected cucumber, the cause of the disease was identified – fungus-like organisms (Oomycetes) of the genus Pythium. In soilless cultivation systems, they cause soft rot of the roots and the shoot base of cucumber and the so-called sudden wilting of a cucumber. Typical symptoms of infection are stunted plant growth, brown discoloration of the root tips and wilting of the plant during the warmer times of the day (they regain turgor during the night). Infected plants turn yellow and die. Infection can occur all year round. In summer, thermophilic species are the most serious problem, while in winter and early spring, spe¬cies preferring lower temperatures. The samples delivered to the Clinic were dominated by the species Globisporangium ultimum (Trow) Uzuhashi, Tojo & Kakish commonly known as Pythium ultimum Trow. The importance of Pythium spp. in the cultivation of cucumber under cover increases year by year, taking into account the frequency of occurrence in the samples delivered to the Clinic.

Fusarium Crown Rot Reduces Water Use and Causes Yield Penalties in Wheat under Adequate and above Average Water Availability

The cereal disease Fusarium crown rot (FCR), caused by the fungal pathogen Fusarium pseudograminearum, is a worldwide major constraint to winter cereal production but especially in Australia’s northern grain’s region (NGR) of NSW and Queensland. Conventionally, FCR induced yield penalties are associated with semi-arid water-limited conditions during flowering and grain-filling. In this study, yield penalties associated with FCR infection were found to be significant under both adequate and above average water conditions which has implication for global wheat production in more favorable environments. This research was conducted to understand the impact of FCR on water availability, yield and grain quality in high protein bread and durum wheat varieties in controlled environment and replicated field experiments across three locations in the NGR over a two-year period. Under controlled conditions, FCR infection significantly decreased water use by 7.5% with an associated yield reduction of 9.5% irrespective of water treatment. Above average rainfall was experienced across all field experimental sites in both 2020 and 2021 growing seasons. The field studies demonstrated a decrease in water use of upwards of 23% at some sites and significant yield penalties across all cultivars of up to 18.4% in natural rainfed scenarios to still 13.2% with further supplementary irrigation.

Evaluating Stratified Substrates Effect on Containerized Crop Growth under Varied Irrigation Strategies

Growers rely on soilless substrates to provide sufficient water and nutrients to containerized crops. Traditional bark-based substrates are engineered to have relatively low water-holding capabilities, which can lead to nonuniform rewetting patterns and inefficient usage of water resources. Engineering substrates to redistribute water dynamics and maximize aeration within the container may improve water resource efficiencies. The goal of this study was to evaluate whether more efficient irrigation schedules can be used when stratifying unique substrates within a container for added crop water and nutrient efficiency. Loropetalum chinense ‘Ruby’ liners were planted and grown in a conventional pine bark substrate or one of three stratified substrate treatments, including a bark:peat, bark:coir, or fine bark layered on top of a coarse bark. The crops were grown under four different irrigation schedules, including single daily application, single application at deficit levels, cyclic application, or cyclic at deficit schedules. Stratified substrates improved crop growth, quality, and yield when compared with plants grown in conventional bark in the single application irrigation treatment. Measured at final harvest, substrates positively influenced plant growth index (P < 0.0001), whereas irrigation scheduling alone had no effect (P = 0.6321). There was a strong interaction between substrate and irrigation schedules on Δ growth index (P = 0.0141). There were strong substrate effects on shoot dry weight (P = 0.0060), root dry weight (P = 0.0342), and growth index (P = 0.0040). The stratified bark:coir treatment outgrew all other substrate treatments. In addition, within all irrigation treatments, plants grown with the stratified bark:coir substrate had the highest survival ratings among the other substrate treatments, whereas the conventional bark had the lowest survival rates. Substrate and irrigation had an effect on nitrogen and potassium leachate concentrations levels (P = 0.0107 and P = 0.0004, respectively). Evaluation of microbial communities showed that substrate (P = 0.0010) and the stratified layer (P = 0.0010) had strong influences on the type of community present and the relative abundance in the treatments used herein this study. Specifically, within cyclic scheduling, bark:peat actinomycete populations were significantly greater than other substrate treatments. Furthermore, under deficit irrigation, stratified substrate systems were able to mitigate crop water stress. The results indicate that when crops such as the Loropetalum are grown in the stratified system, crop growth can be sustained when drought conditions are present. This is possible by providing adequate water availability even under low water inputs until subsequent irrigations during the fragile establishment period, when compared with using traditional bark-based substrates.

Seedling physiological responses from Ceiba glaziovii (Kutze) K. Skum. to intermittent drought events

The Brazilian Dry Tropical Forest, called Caatinga, has several environmental conditions limiting plant growth and development, requiring the plants that inhabit this phytogeographic domain, physiological and morphological traits to guarantee the perpetuation and survival of the species. The objective of the present work was to evaluate the growth parameters in Ceiba glaziovii, a tree species that occurs in the Caatinga, submitted to intermittent drought. For such seedling of C. glaziovii were subjected to different cycles of irrigation suspension [Control- daily irrigation, S7- irrigation every seven days and SS - total suspension of irrigation until signs of wilt appear]. Height, number of leaves, stem diameter, dry matter of the various organs, root / shoot ratio, leaf area, and the index of plasticity were evaluated. The prolongation of intermittent drought had a significant reducing effect on the growth rates, dry matter production and leaf area of stressed C. glaziovii seedlings compared to daily watering ones. Plant height and stem diameter were the most plastic traits found (IP>0,8). Thus, watering intervals above seven days may severely compromise the production of C. glaziovii seedlings, affecting the growth rates until the accumulation of dry matter. These results demonstrate that this species does not show great tolerance to drought stress during the initial period of its development, suggesting for cultivation of seedlings an adequate water availability or an interval of up to seven days between watering.

Climate Change and Utah Ski Resorts: Impacts, Perceptions, and Adaptation Strategies

Climate change is a threat to ski resorts, the ski industry, and mountain communities that rely on ski tourism. Ski resorts may be able to mitigate some of the social and economic impacts caused by climate change with proactive adaptation strategies. Using historical weather data, future climate projections, and interviews with ski resort managers in Utah (United States), this research investigates the effects of climate change on ski resorts across the state. We examine temperature change at all resorts within the state from 1980–2018 and climate projections from 2021–2100 under different climate change scenarios (RCPs 2.6, 4.5, and 8.5). We also report on semistructured interviews with resort managers to provide insights into how resort leadership perceives the impacts of climate change, is implementing adaptation strategies, and is addressing barriers to adaptation. Many resorts in Utah are warming faster than global averages, and minimum temperatures are rising faster than maximum temperatures. By the end of the century, winter (December–March) minimum daily temperatures in Utah could warm an additional 6.0°C under the RCP 8.5 scenario near northern Utah resorts and 6.6°C near southern Utah resorts. Resort managers are concerned about shorter season lengths, shifting ski seasons, less snow cover, and poorer snow quality. Many resorts are already adapting, with the most common adaptations being snowmaking and diversifying outdoor recreation offerings (particularly during the summer and shoulder seasons). Barriers to adaptation reported by managers include financial costs, adequate water availability for snowmaking, and uncertainty about climate change projections. Climate change is already impacting Utah ski resorts, but adaptation practices can reduce the negative impacts to some degree at most resorts.

Trichoderma asperellum Inoculation as a Tool for Attenuating Drought Stress in Sugarcane.

Drought stress is an important concern worldwide which reduces crop yield and quality. To alleviate this problem, Trichoderma asperellum has been used as a plant growth-promoting fungus capable of inducing plant tolerance to biotic and abiotic stresses. Here, we examined the effect of T. asperellum inoculation on sugarcane plant above and belowground development under drought stress and investigated the role of this fungus on inducing tolerance to drought at physiological and biochemical levels. The experiment was performed in pots under greenhouse conditions, with four treatments and four replicates. The treatments consisted of sugarcane plants inoculated or not with T. asperellum and grown under drought stress and adequate water availability. Drought-stressed sugarcane plants inoculated with T. asperellum changed the crop nutrition and chlorophyll and carotenoid concentrations, resulting in increased photosynthesis rate, stomatal conductance, and water use efficiency compared to the non-inoculated plants. In addition, the antioxidant metabolism also changed, increasing the superoxide dismutase and peroxidase enzyme activities, as well as the proline concentration and sugar portioning. These cascade effects enhanced the root and stalk development, demonstrating that T. asperellum inoculation is an important tool in alleviating the negative effects of drought stress in sugarcane. Future studies should be performed to elucidate if T. asperellum should be reapplied to the sugarcane ratoons.

Potential Location for Extensification of Organic Rice Field in Tasikmalaya District

Tasikmalaya District is one of the districts that have succeeded in producing export quality organic rice. Organic rice export demand reaches 320 tons per year, while the amount of organic rice production produced is only 20-30 tons, which means it has not been able to fulfill market demand. This potential should be utilized by increasing the amount of organic rice production, one of which is through extensification. The purpose of this study is to determine potential locations for the extensification of organic rice fields as an effort to increase organic rice production to meet market share. This study uses quantitative method and conducts analysis on land capability, land suitability, and irrigation water. The result of the study states that the cultivation area is 14,860.53 hectares, where 10,155.01 hectares of it is suitable for developing rice fields with adequate water availability that can fulfill the water needs of the rice fields

Towards sustainable water resource management in rural Nigeria: The role of communities

Access to water is crucial for healthy living and survival. In developing countries such as Nigeria, rural communities often suffer from a severe shortage of the supply of fresh, potable water. The need to change the tide has led to the inclusion of the adequate availability of water for allas one of the 2030 United Nations Sustainable Development Goals. Evidence shows that the lack or poor supply of freshwater could lead to a prevalence of waterborne diseases and might negatively affect economically important activities. While water sustainability deals with ensuring adequate supply of water for the present and future generations, water resource management is the strategy for achieving water sustainability. Considering the above, this article examines the literature on water resource management vis-à-vis the legal framework for water management in Nigeria. The article notes that rural communities in the country have a critical role to play in water resource management in the country and in the quest to attain the goals for water. It is recommended that policies should be implemented to provide for sustainable management of water as well as a strategy for educating rural communities on what they must do to achieve the Sustainable Development Goals for water management in Nigeria at the rural community level. For example, there is a need to provide for private sector led water development projects in rural areas backed by government subsidy as well as programmes to enlighten community leaders on their role in ensuring water sustainability.
 Keywords: Water, access to water, legal framework for water management, rural area, SDGs, Nigeria.

Framework for the implementation of an Internet of Things (IoT)-based water distribution and management system.

This study aims to identify issues plaguing rural India's water supply chain and present a general methodology for the implementation of an IoT-based water distribution and management system in a rural setting. Through the literature review, significant hurdles in the water supply chain of rural India, as well as the potential role of IoT in water supply chain management, were recognized. An implementation plan was proposed to design an IoT-based water distribution and management system with the help of flow meters, ultrasonic sensors, motors, etc. Also, the feasibility of such a system was explored with the help of a use case. This study highlighted that one of the most significant reasons for water scarcity in rural India is the lack of proper infrastructure leading to water resources mismanagement. In the context of our use case, despite adequate availability of physical water for consumption, by the time water is delivered to the consumers, a significant amount of it is wasted due to the lack of an efficient water management system. It was determined that the investment return for the proposed system would break even within three months of installment. This study's results are based on inputs from governmental data collected in the Census report of 2011. As such, the ground level scenario is bound to be comparatively different today. This study is anticipated to guide governmental organizations and policymakers in the formulation of new strategies.Graphic abstract

Additional Income Generation from Cultivation of Summer Mungbean in Rice-Wheat System of Haryana

Background: Mungbean [Vigna radiata (L.) Wilczek], also known as green gram is cultivated on area of 4.75 million ha in kharif and rabi/ spring seasons as monocrop or intercrop in India. It serves as a major source of dietary protein for the vast majority of vegetarian people in the country. Mungbean contributed 10.03 per cent of total pulses production (23.40 million tonnes) in the country with productivity level of 494 kg ha-1 in 2018-19. The pulses cultivation in Haryana is almost eliminated in kharif season owing to deviation of area towards cotton, cluster bean and pearlmillet because of low profitability. However, the new window opens for cultivation of mungbean in rice-wheat cropping system in summer season to generate additional farm income and to improve soil health. The area under summer mungbean in state was around 64 thousand ha with the production of 50 thousand tonnes and the average productivity of 780 kg/ha during 2017-18. Although rice-wheat system provides better farm returns, but it has imposed threat to soil health, availability and contamination of ground water, weed and biotic stress management. Methods: The data pertains to costs and returns from summer mungbean cultivation was gathered from 60 mungbean cultivators of Hisar, Kurukshetra and Panipat districts of Haryana having adequate irrigation water availability adopting personal interaction approach in 2018-19. Simple budgeting technique was employed to draw practical implications which ultimately help to take favourable policy decisions for enhancing acreage of summer mungbean. Result: The inquiry profound that mungbean cultivation in summer season particularly in rice-wheat was established as additional income generation farm enterprise. The net benefits accrued from short duration varieties of mungbean over variable cost was Rs. 31831 ha-1 with time span of 60-70 days by utilizing fallow land in summer season. The B-C ratio toiled considering expenses incurred on variable resources with value of 2.99 divulges economic viability of mungbean cultivation in the study area. It is imperative from results that cultivation of short duration cultivars of mungbean is viable option to enhance farm income, restoration of diminishing soil fertility owing to adoption of continuous rice-wheat rotation by inherent characteristics of converting atmospheric nitrogen. Distinctive efforts are essential to evolve mungbean cultivars suitable to prevailing cropping system in Haryana and assure market procurement. The exploration of mungbean cultivation will reduce dependency on import and improve net availability of pulses in India.

Nitrogen Utilization from Ammonium Nitrate and Urea Fertilizer by Irrigated Sugarcane in Brazilian Cerrado Oxisol

Sugarcane is the most promising among renewable biofuel-producing crops. An adequate availability of water and nutrients, especially nitrogen (N), is of utmost importance. From the hypothesis that the source and the rate of N fertilization influence the N use efficiency of an irrigated soil–sugarcane system, this study aimed to evaluate the stalk and crop residues (pointer and leaves) yield, as well as the N utilization, from different rates of ammonium nitrate and urea by irrigated sugarcane in the cane plant cycle, using an 15N isotopic dilution technique. The soil used for the experiment was an Oxisol (Rhodic Haplustox) Cerrado (savannah) phase. The experiment was carried out at a farm of the Raízen Mill, which was located in the municipality of Jataí, Goias State, Brazil. The sugarcane variety IACSP95–5000 was used in a randomized block design, with three replicates, four N rates (30, 60, 120, and 180 kg ha−1), and two fertilizer sources labeled with 15N isotopes (urea and ammonium nitrate). The average value for N utilization was 60.17% for the ammonium nitrate source and 44.95% for urea. The responses in the percentage and quantity of N in the sugarcane from the fertilizer increase with the increasing N rate. The soil was the main N source for sugarcane. The higher stalk and pointer yield was recorded at the average rate of 143.61 kg N ha−1. Further studies are needed to evaluate the residual effect of N in the next cycles.

Intensive Mechanical Site Preparation to Establish Short Rotation Hybrid Poplar Plantations—A Case-Study in Québec, Canada

Because they generate more wood per area and time, short rotation plantations are likely to play an increasing role in meeting the global increase in the demand for wood fiber. To be successful, high-yield plantations require costly intensive silviculture regimes to ensure the survival and maximize yields. While hybrid poplar (Populus spp.) is frequently used in intensive, short rotation forestry, it is particularly sensitive to competition and resource levels. Mechanical site preparation is thus of great importance to create microsites that provide sufficient light levels and adequate soil water and nutrient availability. We conducted an experiment in Québec (Canada) to compare two intensive site preparation treatments commonly used to establish hybrid poplar. We compared the effects of double-blade site preparation (V-blade), mounding and a control on hybrid poplar growth and nutritional status four growing seasons after planting on recently harvested forested sites. We also evaluated the effects of site preparation and planted poplar on inorganic soil N. Our results confirmed general positive effects of site preparation on the early growth of hybrid poplar clones. After four growing seasons, survival was higher in the mounding treatment (99%) than in the V-blade (91%) and the control (48%). Saplings planted in the V-blade and in the mounding treatments had mean diameters that were respectively 91% and 155% larger than saplings planted in the control plots. Saplings were 68% taller in the mounding treatment than the control plots, but differences between the V-blade and controls were not significant. We did not detect significant effects of site preparation or the presence of planted hybrid poplar on soil inorganic N. Sapling foliar nutrient concentrations were not influenced by the site preparation treatments. Based on these results, mounding appears to be a good management approach to establish hybrid poplar plantations under the ecological conditions we have studied, as it is less likely to cause erosion because of the localized nature of the treatment. However, these environmental benefits need to be balanced against economic and social considerations.

Sunflower growth and yield response to sewage sludge application under contrasting water availability conditions

Good knowledge of crop response to biosolids is necessary for optimizing their use as soil amendments. The present 2-yr study evaluated the impact of soil application of municipal sewage sludge on growth, dry matter translocation, achene and oil yield as well as on achene Fe, Cu, Zn and Mn content of field-grown sunflower (Helianthus annuus L.) under contrasting water availability in terms of seasonal rainfall. Treatments included three sewage sludge rates (9, 18, and 36 Mg dry weight ha−1 yr−1) compared with inorganic fertilizer (138 kg N plus 24 kg P ha−1 yr−1) and a non-amended control. Adding sewage sludge increased stem diameter, height, and early growth of sunflower plants compared with control. Dry matter at flowering was positively correlated with translocation of dry matter to achenes (r = 0.855**). However, high early dry matter was translated into enhanced achene yield only with adequate water availability along growth cycle, while water shortage resulted in fewer achenes and poor seed-filling. Sewage sludge application increased achene yield even under water shortage, suggesting a beneficial effect of sewage sludge on soil water status. Achene yield with added sewage sludge was similar to or greater than with the inorganic fertilizer. Sewage sludge decreased achene oil concentration and increased achene N concentration, compared with the non-amended control, without affecting Zn, Fe, Mn, and Cu content in achenes even at the high application rate of 18 Mg ha−1. Findings support that sewage sludge addition in soil at the rate of 9 Mg ha−1 was agronomically adequate and could replace inorganic fertilizer in sunflower production, irrespective of seasonal rainfall amount and distribution patterns.