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Reasoned fertilization practices promote fertilizers formula adjusted to the crop's needs and increase production and income. In this study, two agronomic tests were carried out on two sites named Tabligbo (site 1) and Djikame (site 2) on degraded sandy loam soils situated in the south of Togo using inorganic and organic fertilizer quantities obtained from reasoned fertilization. An indigenous variety of Abelmoschus esculentus was used and five treatments were applied: T2: mineral fertilizer (667 kg/ha), T3: waste compost (6126 kg/ha at Tabligbo and 7260 kg/ha at Dzikame), T4: mineral (333.50 kg/ha) + compost fertilizers (3063 kg/ha for site 1 and 3630 kg/ha for site 2), control (T0) and smallholder farmers' old fertilization practices (T1). At Tabligbo, treatments T2 and T4 stimulated quick growth (74,5 ± 03.50 cm) and the highest number of fruit was obtained on T4 treatment (102 ± 09). At Djikame, treatments T2 and T3 presented the highest growth (65.82 ± 2.51 cm) and the T4 treatment gave the best number of fruits (72 ± 4.00). Economic Efficiency and Cost-Value Ratio were high on the T4 formula on Tabligbo soil (53.48% and 1.85). At Djikame, treatment T2 presents the highest value of economic parameters (24.52% and 01.35). Among treatments tested, T4 (compost + mineral fertilizer) is the effective treatment on Tabligbo sandy loam soil for okra production while the T2 (mineral fertilizer) option is the best for okra production on site 2 due to the low content in nitrogen increasing C/N ratio. The effective fertilizer formulas discovered in this study will be shared with farmers in the study areas in order to improve market garden crop production in South Togo. [ABSTRACT FROM AUTHOR]

Controlled release fertilizers (CRFs) mitigate negative effects of high nitrogen (N) fertilization rates, such as N toxicity and soil N loss. However, it is unknown if potentially toxic rates of CRF and quick release fertilizer differentially affect soil bacterial communities. To examine potential N toxicity effects on soil microbial communities, we grew tomato (Solanum lycopersicum "Rutgers") for eight weeks in soils that were fertilized with high levels of quick release or controlled release urea and in soils with either low or high initial microbial N competitor populations. In both soils, we observed N toxicity in urea-fertilized tomatoes, but toxicity was ameliorated with CRF application. Controlled release fertilization increased soil N retention, thereby reducing soil N loss. While N toxicity symptoms manifested in the plant, the soil microbiome was only minorly affected. There were subtle differences in soil bacterial populations, in which nitrifying bacteria accumulated in soils fertilized at high N rates, regardless of the type of N fertilizer used. Ultimately, CRF reduced plant N toxicity symptoms but did not change the soil microbiome compared to quick release urea. These results show that while there are clear benefits of CRF regarding N toxicity tolerance on crops, the soil microbiome is resilient to this abiotic stressor. [ABSTRACT FROM AUTHOR]

In a field experiment from 2020-2023 on the southern chernozems of the Odessa region of Ukraine, we studied the effect of the doses and timing of mineral nitrogen application when growing winter peas on the tuberization process and crop productivity. Mineral nitrogen in doses of 30, 45 and 60 kg/ha in the form of ammonium nitrate was applied in different development phases of winter peas under seedbed cultivation: foliar top dressing with urea solutions during the resumption of spring vegetation, the budding phase and the beginning of grain filling. Winter pea of the Enduro variety was sown annually on October 20, with a row spacing of 15 cm and a rate of 1.2 million germinating seeds per hectare. The previous crop was winter wheat. The conditions of the Southern Steppe of Ukraine for winter sown peas were shown for the first time. The introduction of mineral nitrogen at a rate of 30-60 kg/ha into the soil during sowing inhibited the formation of nodules from the active spring growth phase. The mass of nodules on the roots of pea plants decreased by 30-50% compared to the control variant without nitrogen application. The same norms of mineral nitrogen introduced in early spring during the resumption of vegetation on the leaf in the form of aqueous solutions did not have a negative impact on tuberization. The correlation coefficient between the dose of mineral nitrogen and the number and weight of nodules did not exceed 0.37, indicating a weak relationship between these indicators. The share of influence of mineral nitrogen norms did not exceed 13.7%. With this method of application, the nitrogen content in the vegetative mass of winter peas exceeded the control variant by 18-27%. [ABSTRACT FROM AUTHOR]

The second half of the nineteenth century was marked by the concomitant and entangled processes of the rise of agricultural chemistry and that of the fertiliser trade. Yet, while the two were undoubtedly related, the work of agricultural chemists was not necessarily characterized by the uniform and unequivocal promotion of fertilisers. This article looks at some of the complex ways in which chemists participated in the development of the fertiliser trade by studying how their work was used to ascribe a commercial price to a chemical element. It analyses the contested development of the idea that nitrogen, in particular, could be given a price, and shows how the rise of this quotation lay at the intersection of scientific and commercial considerations. More broadly, it argues that the importance of the new artificial fertilisers primarily lay not so much in yield increases as in inaugurating a new regime marked by a more comprehensive quantitative assessment of inputs and outputs, thereby playing a key role in the industrialisation of agriculture. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at College of Agriculture, Hassan during kharif 2018 to study the growth, yield and quality parameters of fodder oats (Avena sativa L.) under varied dates of sowing and nitrogen application. The experiment was conducted on red sandy loam soil and the experiment was laid out in a factorial RCBD with 10 treatment combinations, which consisted of five different dates of sowing and two nitrogen levels replicated thrice. The results revealed that sowing during first fortnight of June recorded significantly higher plant height (133.42 cm), number of tillers (93.80) 0.5 m-1 row length, leaf to stem ratio (0.76), leaf area (3,766 cm2 0.5 m-1 row length), dry matter accumulation (97.73 g 0.5 m-1 row length) and SPAD readings (29.83), green fodder yield (28.88 t ha-1), dry fodder yield (5.79 t ha-1) crude protein (6.39%), B:C ratio (2.32) as compared to other dates of sowing. Application of 125 kg N ha-1 recorded significantly higher leaf to stem ratio (0.57), SPAD readings (25.46), leaf area (3,151 cm2 0.5 m-1 row length) green fodder yield (23.57 t ha-1), uptake of nitrogen, phosphorous and potassium (96.80 kg ha-1, 16.86 kg ha-1 and 82.11 kg ha-1, respectively) gross returns (Rs.47156/- ha-1) and net returns (Rs.22279/- ha-1) as compared to 100 kg N ha-1. [ABSTRACT FROM AUTHOR]

Studies have been performed on the sod-podzolic medium loamy soil of the Middle Cis-Urals for determining the mineral nutrition factors to ensure obtaining the yield of the Accord rape seeds of at least 1. 50 t/ha. In 2018 - 2019, the introduction of calculated doses of nitrogen (N60-80) fractionally (½ before sowing and ½ as top dressing) in the phase of three to four leaves, followed by subsequent foliar fertilization with the ZnSO4 micronutrient fertilizer (162 g/ha) in the budding phase, helped to obtain the planned yield by increasing the rape plant stand density by 8 plants/m² and the rape plant productivity by 0. 45 g. Improvement of mineral nutrition has increased the area of plant leaves of the crops in the budding phase to 27, 000 m²/ha. With the seed yield of 1. 53 t/ha, rape has ensured the gross fat yield of 687 kg/ha and the protein yield of 320 kg/ha; it has also showed the efficiency of cultivation -- the energy efficiency coefficient of 1. 64 with the cost of 10, 413 rubles per ton of seeds. [ABSTRACT FROM AUTHOR]

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Copyright of Cientifica is the property of Fundacao de Apoio a Pesquisa e Extensao and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Core Ideas: The milpa marceña is an ancient maize agrosystem on herbaceous wetlands "popals" in the dry season.Three improved maize cultivars and the traditional cultivar mején were evaluated.The mején cultivar showed the highest performance.The milpa marceña is compatible with the hydrological dynamics of wetlands and without the use of industrial inputs. Although herbaceous wetlands are one of the most productive ecosystems and their functions provide benefits to humankind, they have been subjected to a number of disturbances over the past 65 yr. Wetlands have been drained to convert them into permanent agricultural land and urban areas, or used by the oil industry or for construction of hydroelectric dams. Moreover, little has been done to innovate the milpa marceña, an ancient maize (Zea mays L.) agrosystem on herbaceous wetlands dominated by hojilla (Thalia geniculata f. rheumoides) named popals in the dry season (March–June). From an agroecological perspective for improving milpa marceña, in a popal soil (Eutric Molic Gleysol), three improved maize cultivars (CP‐560, CP‐561, and CP‐562) and the traditional cultivar mején were evaluated under three planting densities (50,000, 53,000, and 60,000 plants ha–1) with no use of mineral fertilizers, herbicides, or pesticides. The results show that precipitation during the milpa marceña growth cycle was 50% lower than the amount required for a successful maize crop (>1 Mg ha–1), hence avoiding the risk of flooding. Maize cultivars take groundwater and nutrients from popal soil; however, these results suggest that cultivars were subject to N deficiency and water stress in the flowering stage. We concluded that the mején cultivar showed the highest performance, with 3.3 Mg ha–1, i.e., it has attributes not previously considered (e.g., plant × microbe interactions) in plant breeding programs for drought‐tolerant or flood‐tolerant cultivars. There is a need for further research and conservation on the use of popals. [ABSTRACT FROM AUTHOR]

Core Ideas: Decreased atmospheric deposition has led to increased S consumption in winter wheat.Sulfur did not increase yield or grain N concentration at any site.Use of recommended soil testing guides are encouraged. Decreased atmospheric S deposition in the past 20 yr has led to increased S fertilizer consumption in winter wheat (Triticum aestivum L.). Producers often apply S without any soil test information. Experiments were conducted at Lahoma, Lake Carl Blackwell, and Perkins, OK (2011–2013) to assess the effect of N and S applied preplant and foliar on grain yield and grain N for winter wheat. In 2011–2012, urea ammonium nitrate (UAN) was applied preplant at rates of 40 and 80 kg N ha−1 additionally; UAN and urea‐triazone (NSURE) were foliar‐applied at rates of 10 and 20 kg N ha−1. Sulfur was foliar‐applied as gypsum (CaSO4⋅2H2O) at 6 kg S ha−1. In 2013, trials were altered to apply 40 kg N ha−1 as UAN preplant, and 20 kg N ha−1 foliar‐applied. Gypsum rates were adjusted at 0, 3, and 6 kg S ha−1 preplant, and S (MAX‐IN‐S) at 3 and 6 kg S ha−1 was foliar‐applied. Sulfur did not increase grain yield or grain N concentration at any site. The interaction between foliar S and N and preplant S and N was not significant. Sulfur fertilizer application is less likely to benefit this region unless low levels of soil test S are identified before planting. Use of recommended soil‐testing guides are encouraged. Although S applications are encouraged commercially, no response was observed in these trials, and all were on sites where soil organic carbon was low (<8.5 g kg−1), where the possibility of seeing S deficiency was greater. [ABSTRACT FROM AUTHOR]

Core Ideas: Cereal N use efficiency was estimated at 35, 41, 30, and 21% for the world, the United States, China, and India, respectively.There was a trend for increased N fertilizer consumption for agricultural use.Best N fertilizer management practices could improve N use efficiency. Two decades ago, world cereal nitrogen use efficiency (NUE) was documented at 33%. Since then, research addressing NUE has advanced. However, there are no current estimates to communicate whether or not research efforts and recent advances have contributed to improved NUE. With the apparent trends for increasing greenhouse gases, NUE values could be used as a management tool for agronomic and environmental sustainability. Our objective was to provide current estimates and trends of NUE for the world and selected countries for cereal crops cultivated in relatively large quantities. Data from the Food and Agriculture Organization (www.fao.org/faostat) website were used to compute NUE. The difference method was employed to derive NUE and trends. Results indicated that cereal NUE in 2015 was 35, 41, 30, and 21% for the world, the United States, China, and India, respectively. Compared with 33% reported in 1999, there was insignificant trend of increase (r2 = 0.01) from 2002 to 2015 for cereal world NUE (p > 0.05). Low NUE for China and India was due to high N consumption. A slight improvement for the United States from 31% in 2002 to 41% in 2015 (r2 = 0.20) could be a result of using improved cultivars and precision crop management. Increasing cereal NUE in the United States echoes the value of new technologies and the heightened importance of the environment. Recognizing year‐to‐year variability in N fertilizer requirement and implementing a systematic approach that combines agronomic recommendations with improved crop varieties could further improve NUE. [ABSTRACT FROM AUTHOR]

Core Ideas: Grassland is a widespread agroecosystem in the globe; however, not enough attention has been given to link grazing management to soil health.Grazing management practices greatly impact soil quality.Moderate stocking rate are more adequate to keep grassland stability. Pasture management affects soil physical–chemical properties and root depth distribution. Adjusting grazing pressure and N fertilization are key management tools affecting these responses. This study evaluated the effect of N fertilization and stocking rate (SR) on soil physical and chemical attributes and root depth distribution in grazed elephantgrass (Pennisetum purpureum Schum. cv. 381) pastures (2009 and 2010). Treatments consisted of three SR (2.0, 3.9, and 5.8 AU ha−1; 1 AU = animal unit = 450 kg body weight) and three N doses (0, 150, and 300 kg N ha−1 yr−1) on elephantgrass pastures. Response variables included soil bulk density (BD), particle density (PD), total porosity (TP), aggregate stability (AS), water infiltration rate (WIR), light fraction of soil organic matter (LF‐SOM), soil fertility, root length density (RLD), and root biomass. Increased SR resulted in greater BD. Soil bulk density ranged from 1.42 to 1.58 g cm−3 for SR ranging from 2.0 to 5.8 AU ha−1, respectively. The C concentration of the LF‐SOM decreased with increasing SR, ranging from 383 to 174 mg C kg−1 soil. Soil fertility, RLD, and the stock of C and N in the root system varied among soil layers. At the end of 2 yr, SR and N fertilization did not affect TP, WIR, and AS nor influenced soil fertility and root system distribution. Overgrazing led to soil compaction and reduced LF‐SOM, indicating a trend of pasture degradation. Moderate SR resulted in greater LF‐SOM, indicating a positive trend for C accumulation in the long term. [ABSTRACT FROM AUTHOR]

Core Ideas: Limited information is available concerning the effects of nitrogen (N) and golf cart traffic rates on buffalograss roughs.Increasing the N rate, especially from 0 to 1 or 1 to 2 lb N/1000 ft2/year, will increase the ability of buffalograss to better withstand traffic stress from golf carts in traffic situations.Increased late season percent green turfgrass cover and turfgrass quality were observed when applying 2 lb to 3 lb N/1000 ft2/year on buffalograss roughs.Buffalograss was able to maintain adequate green cover and acceptable quality with traffic rates up to 4 traffic passes/week. Buffalograss [Buchloë dactyloides (Nutt.) Engelm.] is increasing in popularity for use in golf course roughs in semiarid climates of the transitional climatic zone due to its low water requirements. Limited information is available concerning the effects of nitrogen (N) and golf cart traffic rates on buffalograss roughs. The objective of this study was to determine the influence of N rate and repeated simulated golf cart traffic on buffalograss maintained at golf course rough mowing height. Three field trials were initiated in July 2014 and 2015 in Manhattan, KS on 'Cody' buffalograss. Treatment factors were four N application rates (0, 1, 2, and 3 lb N/1000 ft2) and five traffic application rates (0, 2, 4, 8, and 16 passes/week) with a custom‐built golf cart traffic simulator. Regardless of traffic rate, as N rate increased, percent green cover (PGC), visual turf quality (VQ), and turf color increased. Results from this study indicate that an increase in N rate, especially from 0 to 1 lb N/1000 ft2/year and from 1 to 2 lb N/1000 ft2/year will increase the ability of buffalograss to better withstand traffic stress during the summer. Although, there may be minimal benefits of applying above 2 lb N/1000 ft2/year on buffalograss roughs. As traffic rate increased, regardless of N rate, buffalograss PGC, VQ, and turf color decreased, especially at 8 and 16 passes/week. Generally, buffalograss was able to maintain adequate PGC and acceptable VQ with traffic rates up to 4 traffic passes/week. We recommend that buffalograss turf managers carefully monitor traffic on buffalograss, especially in high traffic areas in the rough. Results show trafficked buffalograss can maintain adequate PGC and VQ when maintained at varying N levels. [ABSTRACT FROM AUTHOR]

Core Ideas: Soybean leaf senescence and maturation, yield, and seed quality were minimally impacted by soil and foliar‐applied nitrogen.Cultivar differences in maturation, yield, and seed quality were evident.The use of NDVI is an effective technique to describe soybean leaf senescence during maturation. Ohio producers often question whether fertilizing soybeans [Glycine max (L.) Merr.] with nitrogen (N) will increase yield. Foliar‐ and soil‐applied N have been evaluated throughout the Midwestern US, but few studies have compared the response of commercially available foliar N applications to soil‐applied N within the same environments. Additionally, there is limited information on the impacts of N application on soybean maturation and leaf senescence. The objectives of this study were to: (i) evaluate the effect of various rates of soil‐ and foliar‐applied N at different growth stages on the maturation of soybeans; and (ii) quantify the effect on soybean yield and quality (protein and oil) of soil and foliar N application. A field study was conducted in 2017 at two Ohio locations using a randomized complete block design with full factorial of soybean cultivar (one Maturity Group II and one Maturity Group III) and N application treatment (unfertilized control and four N applications varying in source, rate, and timing). The maturity date, yield, and quality varied among cultivars. Leaf senescence was impacted by weather conditions to a greater extent than N application. Maturity date was impacted by N application, but all treatments matured within 1 day of one another and were similar to the untreated control. The N treatments had minimal effects on leaf senescence, yield, seed protein, and seed oil. Future studies should focus on expanding these results in additional environments and with more N application treatments. [ABSTRACT FROM AUTHOR]

Abstract The VegSyst model, initially developed for nitrogen (N) and irrigation recommendations for greenhouse-grown vegetable crops, was adapted for outdoor conditions, for lettuce, spinach and processing tomato. The major change introduced into the existing VegSyst model was to include evaporative demand, as transpiration use efficiency (TUE), as an additional determinant of dry matter production (DMP); PAR radiation being the other determinant. For daily simulation of DMP, VegSyst-Outdoors selects the smallest of the two DMP values calculated using both approaches. Data from studies conducted in different locations and years were used for calibration and validation. For lettuce, data from crops grown in California and Spain were used, for three lettuce types – Crisphead, Romaine and Batavia. One crop of each lettuce type was used for calibration. Different crops of Crisphead and Batavia lettuce were used for validation; no data were available for validation of Romaine lettuce. For spinach, calibration was conducted with data from a winter-grown crop grown in Spain, and validation was done with data from a spring-grown crop in Spain from a different region and year. For processing tomato, the calibration crop was grown in Spain, and validation was conducted with data from 10 different crops from California, Italy and Spain, and from different years. Radiation-use efficiency (RUE) values ranged from 2.1 to 2.8 g MJ−1 PAR for the three lettuce types, and were 2.2 and 2.3 g MJ−1 PAR for spinach and processing tomato, respectively. TUE was different among lettuce types, being 3.8 g kg−1 for Crisphead, 5.0 g kg−1 for Romaine, and 5.4 g kg−1 for Batavia. TUE values for spinach and processing tomato were 5.0 and 5.6 g kg−1, respectively. Following adaptation to outdoor conditions, crop DMP, crop N uptake and crop evapotranspiration (ETc) were accurately simulated in most of the validation crops. The diversity of sites and years of the crops examined demonstrated the robustness of the VegSyst model when adapted to outdoor conditions. Highlights • The VegSyst model for greenhouse crops was adapted for outdoor conditions. • Daily dry matter production (DMP) based on either TUE or RUE. • Adapted model calibrated and validated for lettuce, spinach and processing tomato. • DMP, N uptake and ETc accurately simulated in most validation crops. • Diversity of validation crops demonstrated robustness of adapted model. [ABSTRACT FROM AUTHOR]

Abstract During the past twenty years, the Nordic countries (Denmark, Sweden, Finland and Norway) have introduced a range of measures to reduce losses of nitrogen (N) to air and to aquatic environment by leaching and runoff. However, the agricultural sector is still an important N source to the environment, and projections indicate relatively small emission reductions in the coming years. The four Nordic countries have different priorities and strategies regarding agricultural N flows and mitigation measures, and therefore they are facing different challenges and barriers. In Norway farm subsidies are used to encourage measures, but these are mainly focused on phosphorus (P). In contrast, Denmark targets N and uses control regulations to reduce losses. In Sweden and Finland, both voluntary actions combined with subsidies help to mitigate both N and P. The aim of this study was to compare the present situation pertaining to agricultural N in the Nordic countries as well as to provide recommendations for policy instruments to achieve cost effective abatement of reactive N from agriculture in the Nordic countries, and to provide guidance to other countries. To further reduce N losses from agriculture, the four countries will have to continue to take different routes. In particular, some countries will need new actions if 2020 and 2030 National Emissions Ceilings Directive (NECD) targets are to be met. Many options are possible, including voluntary action, regulation, taxation and subsidies, but the difficulty is finding the right balance between these policy options for each country. The governments in the Nordic countries should put more attention to the NECD and consult with relevant stakeholders, researchers and farmer's associations on which measures to prioritize to achieve these goals on time. It is important to pick remaining low hanging fruits through use of the most cost effective mitigation measures. We suggest that N application rate and its timing should be in accordance with the crop need and carrying capacity of environmental recipients. Also, the choice of application technology can further reduce the risk of N losses into air and waters. This may require more region-specific solutions and knowledge-based support with tailored information in combination with further targeted subsidies or regulations. Highlights • The four Nordic countries have different approaches on agricultural N flows and mitigation measures. • Most countries will need new actions if National Emissions Ceilings Directive targets are to be met. • A solely voluntary and economic approach may not promote the necessary changes needed. • Tailored information and support in concert with targeted subsidies and regulations may be required. • It is important to apply the most cost effective mitigation measures. [ABSTRACT FROM AUTHOR]

High ozone (O3) can cause great damage to plants. However, the effect of high O3 on nitrogen (N) absorption, distribution, and utilization in rice at different growth stages under different planting densities is poorly understood. In the present study, a conventional cultivar (Yangdao 6) and a hybrid cultivar (II You 084) with different planting densities were exposed to an elevated amount of O3 (E-O3; 50% higher than that of the control, C-O3) under a freeair gas concentration enrichment (FACE) system. N absorption, distribution, and utilization of the green leaves, stems, and shoots at tillering, jointing heading, and maturity were investigated. Results showed that E-O3 significantly increased the N content in the shoots of Yangdao 6 by 7.5%, 12.7%, and 19.6%, respectively, at jointing, heading, and maturity. Also, the N content in the shoots of II You 084 increased by 5.4%, 6.5%, and 8.4% at the corresponding growth stage upon E-O3 application. E-O3 significantly decreased N accumulation of II You 084 by 8.3%, 4.9%, 4.7%, and 19.2%, respectively, at tillering, jointing, heading, and maturity. Further, E-O3 had a decreasing effect on the N distribution in green leaves (p ≤ 0.05) of both cultivars, but exerted an increasing effect on that in the stems of both cultivars (p ≤ 0.05). In addition, E-O3 significantly decreased the N use efficiency (NUE) for biomass of the two cultivars in all growth stages. These results revealed that E-O3 could increase the N content in rice plants but decrease the N accumulation and utilization in both cultivars. The effects of E-O3 on N absorption, distribution, and utilization were not affected by planting density. [ABSTRACT FROM AUTHOR]

Highlights • The amount of nitrogen in the substrate increases, the spawn running period of shiitake is shortened. • The yield is not directly correlated with the N, lignin, cellulose content and cellulose:lignin ratio of the substrate. • Shiitake prefers substrates containing a moderate amount of N, hemicellulose and lignin. • The N content of the substrates increases with time. • The amount of lignocellulosic content was reduces in the substrate during the life cycle of mushroom. Abstract The study assessed the changes in digestibility of some agricultural wastes such as chickpea straw (CPS), corn stalk (CS), alfalfa hay (AH) and sunflower head residue (SFH) during the spawn running period and fruitbody production of Lentinula edodes (Berk.) Pegler (shiitake) to better understand the nutritional needs of this mushroom species. In addition, the effects of these wastes on some productivity features of shiitake cultivated under laboratory conditions were evaluated. Oak awdust (OS) was used as a control substrate. The substrates were analyzed for nitrogen (N), cellulose, hemicellulose and lignin content at three different growth stages. Morever, the effect of agro-wastes on spawn run time, time to first primordia initiation, time to first harvest, yield, biological efficiency (BE) and average mushroom weight were evaluated during the cultivation cycle. Among the five substrates, the SFH exhibited maximum productivity, followed by CPS (233.7 g/kg and 228.1 g/kg, respectively). No correlation was found between the shiitake yield and the N or lignocellulosic content of the growing substrates. On the other hand, the shiitake consumed hemicellulose during the spawn running period, whereas the consumption of cellulose and lignin occured during the pinheading and fruiting formation stages. The hemicellulose, cellulose and lignin contents in the spent substrate were 36.5–51.9%, 5.3–27.0% and 24.0–36.8% lower, respectively, than in the initial substrates, while the N content in the mushroom substrate was increased by 10.3% (CS)−97.1% (OS) after shiitake cultivation. In conclusion, shiitake mushrooms had a preference for substrates containing a moderate amount of N, hemicellulose and lignin, and having a low cellulose:lignin ratio. Morever, the chemical composition of the growing substrates changed during the life cycle of the mushroom and the protein content increased with time, while the amount of lignocellulosic content in the substrates was reduced, making it more digestible. [ABSTRACT FROM AUTHOR]

Highlights • Most of the growth parameters were greater in vermiculite than in rockwool. • Dissolved oxygen concentration decreased sharply in rockwool but slightly in vermiculite. • The growth of wasabi plantlets is depressed at low dissolved oxygen concentrations. • A hydroponic system incorporates a 50% or 100% nutrient concentration and vermiculite. • The above-hydroponic system allows high-quality wasabi plantlets. Abstract The growth of wasabi (Wasabia japonica Matsumura) plantlets was compared in four concentrations of standard Enshi nutrient solution (25%, 50%, 100%, and 150%) and two kinds of supporting materials (rockwool and vermiculite) using an in vitro hydroponic culture system for photoautotrophic micropropagation. After 28 days of culture, most of the growth parameters such as fresh weight and dry weight, shoot/root dry weight ratio, and leaf area ratio were highest in wasabi plantlets grown in 50% or 100% nutrient solution, and this enhancement was greater in vermiculite than in rockwool. Dissolved oxygen concentration decreased sharply in rockwool but only slightly in vermiculite during the course of the experiment, resulting in a dissolved oxygen concentration of 8 mg L−1 in the vermiculite and 6 mg L−1 in the rockwool. The highest root nitrogen concentration was observed at a nutrient concentration of 100% in vermiculite and rockwool. The highest net photosynthetic rates were observed on day 28 in vermiculite at nutrient concentrations of 50% and 100%. The growth of wasabi plantlets is depressed through a decrease in root water and nutrient uptake caused by low dissolved oxygen concentrations. These findings clearly demonstrate that a hydroponic system that incorporates a 50% or 100% nutrient solution concentration and vermiculite will allow high-quality wasabi plantlets to be propagated rapidly under photoautotrophic conditions. [ABSTRACT FROM AUTHOR]

Herbivore damage by chewing insects activates jasmonate (JA) signalling that can elicit systemic defense responses in rice. Few details are known, however, concerning the mechanism, whereby JA signalling modulates nutrient status in rice in response to herbivory. (15NH4)2SO4 labelling experiments, proteomic surveys, and RT‐qPCR analyses were used to identify the roles of JA signalling in nitrogen (N) uptake and allocation in rice plants. Exogenous applications of methyl jasmonate (MeJA) to rice seedlings led to significantly reduced N uptake in roots and reduced translocation of recently‐absorbed 15N from roots to leaves, likely occurring as a result of down‐regulation of glutamine synthetase cytosolic isozyme 1–2 and ferredoxin–nitrite reductase. Shoot MeJA treatment resulted in a remobilization of endogenous unlabelled 14N from leaves to roots, and root MeJA treatment also increased 14N accumulation in roots but did not affect 14N accumulation in leaves of rice. Additionally, proteomic and RT‐qPCR experiments showed that JA‐mediated plastid disassembly and dehydrogenases GDH2 up‐regulation contribute to N release in leaves to support production of defensive proteins/compounds under N‐limited condition. Collectively, our results indicate that JA signalling mediates large‐scale systemic changes in N uptake and allocation in rice plants. Exogenous methyl jasmonate applications significantly inhibited N uptake in rice roots and N‐assimilating enzymes, mediated plastid disassembly, and reduced N translocation from roots to leaves. Jasmonate signalling mediates large‐scale systemic changes in N uptake and allocation in rice plants. [ABSTRACT FROM AUTHOR]

Abstract Indirect N 2 O emissions from agricultural nitrogen (N) leaching and runoff in water bodies contribute significantly to the global atmospheric N 2 O budget. However, considerable uncertainty regarding this source remains in the bottom-up N 2 O inventory. Indirect N 2 O emission factor associated with N leaching and runoff (EF 5 ; kg N 2 O N per kg of NO 3 −−N) incorporate three components for groundwater and surface drainage (EF 5g), rivers (EF 5r), and estuaries (EF 5e). The 2006 IPCC default EF 5 value was based on a small number of studies available at the time. Here we present the synthesis of 254 measurements of EF 5 , dissolved N 2 O, and nitrate from 106 studies. Our results do not support the further downward revision of EF 5g by the IPCC and suggest an upward revision of EF 5g of 0.0060. The emission factors for groundwater and springs (0.0079) was higher than that for surface drainage (0.0040). The emission factor for lakes, ponds, and reservoirs was 0.0012, whereas that for rivers was 0.0030, and a combined EF 5r was 0.0026. Estimated EF 5r and EF 5e (0.0026) values from the study were close to the current IPCC default values (0.0025 each). We estimated an updated default EF 5 value of 0.01 for the refinement of IPCC guidelines. Graphical abstract Image 1 Highlights • We summarized 254 field data on indirect emission factor from N leaching and runoff. • Mean emission factor (EF) for ground water and surface drainage (EF 5g) was 0.0060. • Mean EF for lakes, ponds & reservoirs, and rivers (EF 5r) was 0.0026. • Mean EF for estuaries (EF 5e) was 0.0026. • Combined EF (EF5) was 0.01, higher than IPCC 2006 default EF (0.0075). We summarized 254 field datasets and estimated indirect N 2 O emission factor from leaching and runoff of agricultural N (EF 5) of 0.01, higher than IPCC 2006 default EF (0.0075). [ABSTRACT FROM AUTHOR]

Highlights • N supply promoted broccoli growth by improving LAI, rather than RUE. • N crop demand and RUE were assessed close to 186 kg ha-1 and 3.2 g MJ-1. • 'Naxos' and 'Parthenon' were more stable than 'Ironman' between years. • Two N critical curves are proposed to be selected on the base of cultivar stem size. Abstract Adequate nitrogen (N) availability must be ensured in broccoli as it is a high N demand crop, however the N not taken up may cause ground and surface water pollution. Both species-specific growth and N demand predicting models could be useful for rational N fertilization management. Two field experiments were conducted on three broccoli cultivars grown at different N fertilization levels [0 (N 0), 75 (N 75), and 100 (N 100) kg ha−1] and under Southern Italian/Mediterranean conditions (i) to study the growth and the N uptake and (ii) to determine the critical N dilution curve for this crop. Nitrogen fertilization prompted crop growth during the linear phase (growth rate ∼9.0 g m-2 d-1 of dry weight - DW) as a result of the enhancement of the intercepted photosynthetically active radiation (IPAR) and of the efficiency in using IPAR for producing dry biomass (RUE). However, the effect of N fertilization on final aboveground dry biomass production (ADW) (∼4.6 Mg ha-1) was affected by the cultivar specific response to the seasonal variability of the temperature time course. In the 'Ironman' cultivar, N nutrition was less effective under suboptimal temperatures, in enhancing ADW and N uptake, because of the reduced leaf growth and IPAR. On the contrary, in 'Naxos' and 'Parthenon' N fertilization was more effective in limiting the effect on plant growth of the sub-optimal temperatures. Under such conditions, despite a slow reduction in IPAR, both cultivars enhanced RUE, with a concomitant increase in specific leaf N. 'Naxos' and 'Parthenon' gave higher and more stable yields, ADW, harvest index (HI) and N uptake over the two seasons. Among the N rates, the best N use efficiency in terms of yield (Partial Factor Productivity) and head dry weight gain (Agronomical NUE) per unit of applied N fertilizer, was obtained with the rate of 75 kg ha-1. At the highest N rate, ADW and yield slightly increased, with no effect on HI. Hence, this rate might be considered close to the optimal under the conditions of the experiment. Two cultivar-specific N dilution curves for broccoli have been proposed to account for the difference which emerged between' Parthenon' and the other broccoli cultivars mainly for the differences related to the proportion of stems on ADW. Both curves underline that this crop maintains a relatively high fraction of photosynthetically active tissue approaching the harvest compared to other brassicas. [ABSTRACT FROM AUTHOR]

For 50 years, UC Agriculture and Natural Resources (UC ANR) has contributed to dairy water quality policy in California and helped, with partner organizations, to implement it in the dairy industry. When conditional waivers for waste discharge requirements expired in 2003, UC ANR shared research and best professional practices as regional water quality control boards developed new orders. UC ANR academics then worked with water quality control boards' staff and dairy industry representatives to develop feasible, staged implementation plans. Collaboratively, more than 50 hours of workshop curriculum were developed and disseminated, helping dairy producers to accept scientifically sound management practices that are more protective of groundwater. Research by UC ANR to better understand system dynamics, nitrogen management and practices to minimize the impact of manure application on groundwater quality continues, as does a program in environmental stewardship. [ABSTRACT FROM AUTHOR]

Field experiments were conducted to investigate the influence of varying levels of water and nitrogen at grain filling stage on 2-acetyl-1-pyrroline (2-AP) content, enzymes activities and grain yield of fragrant rice (Oryza sativa L.). Two fragrant rice cultivars i.e., 'Basmati 385' and 'Nongxiang 18', were grown under two water treatments i.e., W1: well-watered (water layer 4-6 cm) and W2: mild soil drought, (the soil water potential was ?(25 ± 5 kPa)) from full heading stage to maturity during early and late season, 2014 at South China Agricultural University, Guangzhou, China. Two nitrogen levels i.e., N1: 15 kg hm-2 and N2: 30 kg hm-2 were applied at heading stage. Results showed that the W2 and N1 treatment improved 2-AP content in brown rice for both cultivars. Higher 2-AP content was observed in the W2N1 treatment in 'Basmati 385' (26.22 and 136.29 ng g-1) and 'Nongxiang 18' (23.47 and 66.48 ng g-1). Moreover, 2-AP content in brown rice showed positive correlation with proline dehydrogenase (PDH) activity whilst showed negative correlation with proline content in grains during both seasons. In addition, 2-AP content in brown rice showed significantly negative correlation with proline for early season, but significant and positive correlation with PDH activity in grains for late season. During early season, all treatments were found no statistically difference for grain yield of both rice cultivars, whereas the highest grain yield i.e., 7.39 and 8.07 t hm-2 was obtained under W2N1 treatment in 'Basmati 385' and 'Nongxiang 18', respectively during late season. In conclusion, mild drought conditions in combination with the N application at 15 kg hm-2 at grain filling stage could promote grain yield and 2- AP content in brown rice. [ABSTRACT FROM AUTHOR]

A field experiment was carried out during the two successive winter seasons of 2014/2015 and 2015/2016 at a private farm in El-Tour region, South Sinai Govemorate, Egypt, to study the effect of planting dates, nitrogen sources and their interactions on dry weight, yield and its components and nitrogen use efficiency (NUE) of garlic (Balady cultivar) grown in sandy soil conditions using drip irrigation system. The obtained results could be summarized as follows: The interaction between planting dates on 15th Oct. or 1th Nov. and fertijizing plants with 100% of the recommended rate (RR) of N as poultry manure (PM) or and 50% RR ofN as ammonium sulphate (AS)+50% RR of N as PM gave the highest values of each of dry weight of bulbs, leaves, and total dry weight/plant at 135 days after planting (DAP), N and P uptake by bulbs and leaves and total uptake of them by plant. yield of grades 1,2, exportable, marketable, total yield, average bulb weight and the highest values of nitrogen use efficiency (NUE). Whereas, the interaction between planting on 15th Oct. and fertilizing plants with 50% RR of N as AS + 50% RR of N as PM gave the highest values of K uptake by bulbs and leaves as well as K total uptake by plant. [ABSTRACT FROM AUTHOR]

Potassium (K) as a macro nutrient governs important physiological mechanisms ensuring optimum plant growth and produce quality. An experiment was conducted during the summer of 2017 to study the effects of potassium application on maize under high nitrogen (N) nutrition with optimum and reduced irrigations. The experiment was comprised of three factors, viz. two irrigation levels (optimum, reduced), three potassium levels (80, 120 and 160 kg ha-1) and four nitrogen levels (100, 150, 200 and 250 kg ha-1). Two separate trials were carried out in randomized complete block design (RCBD), one under optimum (five irrigations) and another under reduced irrigation (three irrigations). One control plot (0K, 0N) was used under each replication for both trials. Optimum irrigation had resulted in maximum days of tasseling, silking, physiological maturity, crop growth rate (CGR), net assimilation rate (NAR), absolute growth rate (AGR), plant height, grains ear-1, thousand grains weight, biological yield, grain yield, chlorophyll contents and shelling percentage. High N (250 kg ha-1) delayed tasseling, silking and physiological maturity and resulted in maximum growth, physiological traits and biological yields. However, 150 kg N ha-1 had resulted in maximum number of ears m-2, number of grains ear-1, thousand grains weight and grain yield. While 100 kg N ha-1 had resulted in early tasseling, silking and physiological maturity. Potassium fertilization at the rate of 160 kg ha-1 delayed phenology and recorded with maximum growth rates, improved physiology and maximum yield traits and grain yield. However, the treatment 120 kg K ha-1 remained almost statistically similar to the 160 kg K ha-1 for most of the parameters. In the case of control vs rest, generally the performance of the control plot was poor. Hence, 150 kg N ha-1 with 120 kg K ha-1 under optimum irrigation is recommended for optimum productivity of maize crop. [ABSTRACT FROM AUTHOR]

Nutrient loss reduction strategies have recently been developed in the U.S. Midwest to decrease the environmental footprint associated with nitrogen (N) fertilizer use. Although these strategies generally suggest decreasing N rates and shifting the timing of N application from fall to spring, the spatiotemporal impacts of these practices on maize yield and fertilizer N use efficiency (NUE, kg grain yield increase per kg N applied) have not been assessed at the watershed scale using crop simulation models. We simulated the effects of N fertilizer rate (0, 168, 190, 224 kg N ha-1) and application timing [fall-applied N (FN): 100% N applied on 1 December; spring-applied N (SN): 100% N applied 10 days before planting; split N: 66% N applied on 1 December + 34% N applied 10 days before planting] on maize grain yield (GY) across 3042 points in Illinois during 2011–2015 using the DSSAT-CERES-Maize model. When simulations were scaled up to the watershed level, results suggest that increases in average maize GY for SN compared to FN occurred in years with higher than average winter rainfall (2011, 2013), whereas yields were similar (+/- 4%) in 2012, 2014, and 2015. Accordingly, differences in NUE for SN compared to FN were small (0.0–1.4 kg GY/kg N) when cumulative winter rainfall was < 300 mm, but increased to 0.1–9.2 kg GY/kg N when winter rainfall was > 500 mm at both 168 kg N ha-1 and 224 kg N ha-1. The combined practice of reducing N fertilizer amounts from 224 kg N ha-1 to 190 kg N ha-1 and shifting from FN to SN resulted in a wide range of yield responses during 2011–2015, with the probability of increasing yields varying from <10% to >70% of simulation points within a watershed. Positive impacts on both GY and NUE occurred in only 60% of simulations for this scenario, highlighting the challenge of simultaneously improving yield and NUE with a 15% N rate reduction in this region. [ABSTRACT FROM AUTHOR]