Crop model calibration and validation is vital for establishing their credibility and ability in simulating crop growth and yield. A split–split plot design field experiment was carried out with sowing dates (SD1, SD2 and SD3); maize cultivars (ZMS606, PHB30G19 and PHB30B50) and nitrogen fertilizer rates (N1, N2 and N3) as the main plot, subplot and sub-subplot with three replicates, respectively. The experiment was carried out at Mount Makulu Central Research Station, Chilanga, Zambia in the 2016/2017 season. The study objective was to calibrate and validate APSIM-Maize and DSSAT-CERES-Maize models in simulating phenology, mLAI, soil water content, aboveground biomass and grain yield under rainfed and irrigated conditions. Days after planting to anthesis (APSIM-Maize, anthesis (DAP) RMSE = 1.91 days; DSSAT-CERES-Maize, anthesis (DAP) RMSE = 2.89 days) and maturity (APSIM-Maize, maturity (DAP) RMSE = 3.35 days; DSSAT-CERES-Maize, maturity (DAP) RMSE = 3.13 days) were adequately simulated, with RMSEn being <5%. The grain yield RMSE was 1.38 t ha−1 (APSIM-Maize) and 0.84 t ha−1 (DSSAT-CERES-Maize). The APSIM- and-DSSAT-CERES-Maize models accurately simulated the grain yield, grain number m−2, soil water content (soil layers 1–8, RMSEn ≤ 20%), biomass and grain yield, with RMSEn ≤ 30% under rainfed condition. Model validation showed acceptable performances under the irrigated condition. The models can be used in identifying management options provided climate and soil physiochemical properties are available.
作物模型的校准和验证对于建立其模拟作物生长和产量的可信度和能力至关重要。按播期(SD1、SD2和SD3)进行分畦设计田间试验;玉米品种(ZMS606、PHB30G19和PHB30B50)和氮肥施量(N1、N2和N3)分别为主、次、次小区，每3个重复。该实验于2016/2017年度在赞比亚奇兰加的马库鲁山中央研究站进行。研究目的是对旱作和灌溉条件下APSIM-Maize和DSSAT-CERES-Maize模型模拟物候、mLAI、土壤含水量、地上生物量和粮食产量的能力进行标定和验证。种植至开花天数(APSIM-Maize)，开花(DAP) RMSE = 1.91 d;DSSAT-CERES-Maize，花期(DAP) RMSE = 2.89 d)和成熟期(APSIM-Maize，成熟期(DAP) RMSE = 3.35 d;充分模拟DSSAT-CERES-Maize，成熟期(DAP) RMSE = 3.13天，RMSE <5%。籽粒产量RMSE分别为1.38 t ha - 1 (APSIM-Maize)和0.84 t ha - 1 (DSSAT-CERES-Maize)。APSIM-和dssat - ceres - maize模型准确模拟了旱作条件下的粮食产量、粒数m−2、土壤含水量(土层1-8层，RMSEn≤20%)、生物量和粮食产量，RMSEn≤30%。模型验证在灌溉条件下表现良好。在气候和土壤理化性质可用的情况下，这些模型可用于确定管理方案。
{"title":"Evaluating APSIM-and-DSSAT-CERES-Maize Models under Rainfed Conditions Using Zambian Rainfed Maize Cultivars","authors":"Charles Bwalya Chisanga, E. Phiri, V. Chinene","doi":"10.3390/nitrogen2040027","DOIUrl":"https://doi.org/10.3390/nitrogen2040027","url":null,"abstract":"Crop model calibration and validation is vital for establishing their credibility and ability in simulating crop growth and yield. A split–split plot design field experiment was carried out with sowing dates (SD1, SD2 and SD3); maize cultivars (ZMS606, PHB30G19 and PHB30B50) and nitrogen fertilizer rates (N1, N2 and N3) as the main plot, subplot and sub-subplot with three replicates, respectively. The experiment was carried out at Mount Makulu Central Research Station, Chilanga, Zambia in the 2016/2017 season. The study objective was to calibrate and validate APSIM-Maize and DSSAT-CERES-Maize models in simulating phenology, mLAI, soil water content, aboveground biomass and grain yield under rainfed and irrigated conditions. Days after planting to anthesis (APSIM-Maize, anthesis (DAP) RMSE = 1.91 days; DSSAT-CERES-Maize, anthesis (DAP) RMSE = 2.89 days) and maturity (APSIM-Maize, maturity (DAP) RMSE = 3.35 days; DSSAT-CERES-Maize, maturity (DAP) RMSE = 3.13 days) were adequately simulated, with RMSEn being <5%. The grain yield RMSE was 1.38 t ha−1 (APSIM-Maize) and 0.84 t ha−1 (DSSAT-CERES-Maize). The APSIM- and-DSSAT-CERES-Maize models accurately simulated the grain yield, grain number m−2, soil water content (soil layers 1–8, RMSEn ≤ 20%), biomass and grain yield, with RMSEn ≤ 30% under rainfed condition. Model validation showed acceptable performances under the irrigated condition. The models can be used in identifying management options provided climate and soil physiochemical properties are available.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84698403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arati Sapkota, M. Sharma, H. N. Giri, B. Shrestha, D. Panday
Economic use of organic and inorganic fertilizers following their availability is necessary for livestock-based Nepalese farming systems. However, how best to integrate these fertilizers in an appropriate manner is not yet clear. Thus, this study was conducted in the horticulture farm of the Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal from November 2018 to February 2019 to evaluate the effect of organic and inorganic sources of nitrogen (N) on growth, yield, and quality of beetroot (Beta vulgaris L.) varieties. The experiment was laid out in a two factorial randomized complete block design with four replications consisting of two beetroot varieties, i.e., Madhur and Ruby Red, and five N source combinations, i.e., N1: 100% poultry manure (PM), N2: 50% PM + 50% urea, N3: 100% farmyard manure (FYM), N4: 50% FYM + 50% urea, and N5: 100% urea (120:80:40 kg NPK ha−1). Results of this study indicated a significant impact of N sources and varieties on the assessed parameters. During harvest, a significantly higher plant height (41.84 cm), number of leaves per plant (14.68), leaf length (34.56 cm), leaf width (11.38 cm), and beetroot diameter (72.15 mm) were observed in the N2 treatment. Likewise, higher economic (49.78 t ha−1) and biological yields (78.69 t ha−1) were also recorded in the N2 compared to other N sources. Out of the two varieties, the Madhur variety was significantly better in most growth and yield parameters. Similarly, the Madhur variety showed a significantly higher economic (44.49 t ha−1) and biological yields (69.79 t ha−1) compared to the Ruby Red variety. However, the physiological weight loss was higher in the Ruby Red variety. Therefore, the current study suggests that an integration of poultry manure along with the combination of N fertilizer and the Madhur variety is the best combination for quality beetroot production in the Terai region of Nepal.
尼泊尔以牲畜为基础的农业系统需要在获得有机和无机肥料后经济地使用它们。然而，如何以适当的方式最好地结合这些肥料尚不清楚。因此，本研究于2018年11月至2019年2月在尼泊尔Chitwan Rampur的农林大学(AFU)园艺农场进行，以评估有机和无机氮源(N)对甜菜根(Beta vulgaris L.)品种生长、产量和品质的影响。试验采用2因子随机完全区组设计，设4个重复，包括2个甜菜根品种Madhur和Ruby Red，以及N1: 100%禽粪(PM)、N2: 50% PM + 50%尿素、N3: 100%农家肥(FYM)、N4: 50%农家肥+ 50%尿素和N5: 100%尿素(120:80:40 kg NPK ha - 1) 5个氮源组合。研究结果表明，氮源和品种对评价参数有显著影响。收获期，N2处理显著提高了甜菜株高(41.84 cm)、单株叶数(14.68)、叶长(34.56 cm)、叶宽(11.38 cm)和甜菜根直径(72.15 mm)。同样，与其他氮源相比，N2也记录了更高的经济产量(49.78 t ha - 1)和生物产量(78.69 t ha - 1)。在这两个品种中，马杜尔品种在大多数生长和产量参数上都明显更好。同样，Madhur品种的经济产量(44.49 t ha - 1)和生物产量(69.79 t ha - 1)也显著高于Ruby Red品种。然而，红宝石品种的生理减重更高。因此，目前的研究表明，在尼泊尔Terai地区，禽粪与氮肥和Madhur品种的组合是生产优质甜菜根的最佳组合。
{"title":"Effect of Organic and Inorganic Sources of Nitrogen on Growth, Yield, and Quality of Beetroot Varieties in Nepal","authors":"Arati Sapkota, M. Sharma, H. N. Giri, B. Shrestha, D. Panday","doi":"10.3390/nitrogen2030026","DOIUrl":"https://doi.org/10.3390/nitrogen2030026","url":null,"abstract":"Economic use of organic and inorganic fertilizers following their availability is necessary for livestock-based Nepalese farming systems. However, how best to integrate these fertilizers in an appropriate manner is not yet clear. Thus, this study was conducted in the horticulture farm of the Agriculture and Forestry University (AFU), Rampur, Chitwan, Nepal from November 2018 to February 2019 to evaluate the effect of organic and inorganic sources of nitrogen (N) on growth, yield, and quality of beetroot (Beta vulgaris L.) varieties. The experiment was laid out in a two factorial randomized complete block design with four replications consisting of two beetroot varieties, i.e., Madhur and Ruby Red, and five N source combinations, i.e., N1: 100% poultry manure (PM), N2: 50% PM + 50% urea, N3: 100% farmyard manure (FYM), N4: 50% FYM + 50% urea, and N5: 100% urea (120:80:40 kg NPK ha−1). Results of this study indicated a significant impact of N sources and varieties on the assessed parameters. During harvest, a significantly higher plant height (41.84 cm), number of leaves per plant (14.68), leaf length (34.56 cm), leaf width (11.38 cm), and beetroot diameter (72.15 mm) were observed in the N2 treatment. Likewise, higher economic (49.78 t ha−1) and biological yields (78.69 t ha−1) were also recorded in the N2 compared to other N sources. Out of the two varieties, the Madhur variety was significantly better in most growth and yield parameters. Similarly, the Madhur variety showed a significantly higher economic (44.49 t ha−1) and biological yields (69.79 t ha−1) compared to the Ruby Red variety. However, the physiological weight loss was higher in the Ruby Red variety. Therefore, the current study suggests that an integration of poultry manure along with the combination of N fertilizer and the Madhur variety is the best combination for quality beetroot production in the Terai region of Nepal.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83117249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Dhakal, B. R. Baral, K. R. Pokhrel, N. Pandit, Y. K. Gaihre, S. Vista
The optimum dose of fertilizers for crops varies with soil, agro-ecology, and crop management practices. Optimizing application dose is critical to reduce nutrient loss to the environment and increase nitrogen use efficiency (NUE), crop yields, and economic return to farmers. An experiment was conducted to determine the optimum N dose for increasing maize (Zea mays L. cv, Manakamana-3) yield, NUE, and farm profits under rainfed conditions. Five levels of N (0, 60, 120, 180, and 240 kg ha−1), and a non-fertilized treatment were tested in a randomized complete block design with three replications. Effects of each treatment on yield and yield attributing traits, plant lodging and Sterility (plants with no cob or grain formation), NUE, and stay green trait of maize were recorded. Application of N above 120 kg ha−1 (N120) did not have any significant effects on yield and yield components. Nitrogen, at N120 and above, produced highly fertile plants (though sterility slightly increased at N180 and N240), higher N uptake, and lower dead leaf area (18–27%). N120 produced the highest agronomic; yield increase per unit of N application (AEN—26.89 kg grain kg−1 N) and physiological efficiency of N (PEN—42.67 kg grain kg−1 N uptake), and net benefit (USD 500.43). Considering agronomic, economic, and NUE factors, an N dose of 120 kg ha−1 was found optimum for the cultivation of rainfed maize (Manakamana-3) under sandy loam soil.
作物的最佳肥料剂量因土壤、农业生态和作物管理方法而异。优化施用剂量对于减少氮肥对环境的损失、提高氮肥利用效率(NUE)、作物产量和农民的经济回报至关重要。本试验旨在确定在旱作条件下提高玉米(Zea mays L. cv, Manakamana-3)产量、氮肥利用效率和农场利润的最佳施氮量。采用3个重复的随机完全区组设计，试验了5个N水平(0、60、120、180和240 kg ha - 1)和一个未施肥处理。记录了各处理对玉米产量和产量性状、倒伏和不育性(无穗轴和无籽粒)、氮肥利用效率和留绿性状的影响。施氮量大于120 kg ha - 1 (N120)对产量和产量构成无显著影响。氮肥处理在N120及以上时，植株肥力高(N180和N240的不育性略有增加)，氮素吸收量高，死叶面积低(18-27%)。N120的农艺产量最高;每单位施氮量(AEN-26.89 kg粒kg - 1 N)和氮素生理效率(PEN-42.67 kg粒kg - 1 N吸收量)的增产和净效益(500.43美元)。综合考虑农艺、经济和氮肥利用等因素，砂壤土下旱作玉米(Manakamana-3)的最佳施氮量为120 kg ha - 1。
{"title":"Optimizing N Fertilization for Increasing Yield and Profits of Rainfed Maize Grown under Sandy Loam Soil","authors":"K. Dhakal, B. R. Baral, K. R. Pokhrel, N. Pandit, Y. K. Gaihre, S. Vista","doi":"10.3390/nitrogen2030025","DOIUrl":"https://doi.org/10.3390/nitrogen2030025","url":null,"abstract":"The optimum dose of fertilizers for crops varies with soil, agro-ecology, and crop management practices. Optimizing application dose is critical to reduce nutrient loss to the environment and increase nitrogen use efficiency (NUE), crop yields, and economic return to farmers. An experiment was conducted to determine the optimum N dose for increasing maize (Zea mays L. cv, Manakamana-3) yield, NUE, and farm profits under rainfed conditions. Five levels of N (0, 60, 120, 180, and 240 kg ha−1), and a non-fertilized treatment were tested in a randomized complete block design with three replications. Effects of each treatment on yield and yield attributing traits, plant lodging and Sterility (plants with no cob or grain formation), NUE, and stay green trait of maize were recorded. Application of N above 120 kg ha−1 (N120) did not have any significant effects on yield and yield components. Nitrogen, at N120 and above, produced highly fertile plants (though sterility slightly increased at N180 and N240), higher N uptake, and lower dead leaf area (18–27%). N120 produced the highest agronomic; yield increase per unit of N application (AEN—26.89 kg grain kg−1 N) and physiological efficiency of N (PEN—42.67 kg grain kg−1 N uptake), and net benefit (USD 500.43). Considering agronomic, economic, and NUE factors, an N dose of 120 kg ha−1 was found optimum for the cultivation of rainfed maize (Manakamana-3) under sandy loam soil.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87478538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Gatsios, G. Ntatsi, Dionisios Yfantopoulos, P. Baltzoi, I. Karapanos, I. Tsirogiannis, G. Patakioutas, D. Savvas
Manure is a common source of nitrogen (N) in organic farming. However, manure is not always easily available, while the maximum N amount added as animal manure in organic agriculture is restricted by EU regulations. The present study was designed to test whether green manuring with a warm-season legume and intercropping with a cold-season legume can substitute farm-yard manure or compost as N sources in organic greenhouse tomato crops. To test this hypothesis, a winter-spring (WS) tomato crop was installed in February following the incorporation of crop residues of an autumn-winter (AW) tomato crop intercropped with faba bean, which had been fertilized with cowpea residues as green manure. This treatment, henceforth termed legume treatment (LT), was compared with the use of compost or manure as an N fertilization source in both tomato crops. In addition, a combination of compost and LT was also used as a fourth treatment. The results showed that green manuring with legumes and particularly cowpea can contribute a significant amount of N to the following organic tomato crop, through the biological fixation process. Nevertheless, legumes as green manure, or compost, or their combination cannot efficiently replace farmyard manure as an N fertilization source. Compost exhibited a slow mineralization course.
{"title":"Effects of Different Organic Soil Amendments on Nitrogen Nutrition and Yield of Organic Greenhouse Tomato Crop","authors":"A. Gatsios, G. Ntatsi, Dionisios Yfantopoulos, P. Baltzoi, I. Karapanos, I. Tsirogiannis, G. Patakioutas, D. Savvas","doi":"10.3390/nitrogen2030024","DOIUrl":"https://doi.org/10.3390/nitrogen2030024","url":null,"abstract":"Manure is a common source of nitrogen (N) in organic farming. However, manure is not always easily available, while the maximum N amount added as animal manure in organic agriculture is restricted by EU regulations. The present study was designed to test whether green manuring with a warm-season legume and intercropping with a cold-season legume can substitute farm-yard manure or compost as N sources in organic greenhouse tomato crops. To test this hypothesis, a winter-spring (WS) tomato crop was installed in February following the incorporation of crop residues of an autumn-winter (AW) tomato crop intercropped with faba bean, which had been fertilized with cowpea residues as green manure. This treatment, henceforth termed legume treatment (LT), was compared with the use of compost or manure as an N fertilization source in both tomato crops. In addition, a combination of compost and LT was also used as a fourth treatment. The results showed that green manuring with legumes and particularly cowpea can contribute a significant amount of N to the following organic tomato crop, through the biological fixation process. Nevertheless, legumes as green manure, or compost, or their combination cannot efficiently replace farmyard manure as an N fertilization source. Compost exhibited a slow mineralization course.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77548107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Auges Gatabazi, B. Vorster, Mireille Asanzi Mvondo-She, E. Mangwende, Robert Mangani, A. Hassen
South African soils generally lack native Bradyrhizobium strains that nodulate and fix atmospheric nitrogen (N2) in soybeans (Glycine max L.). It is therefore very important to inoculate soybeans with products that contain effective Bradyrhizobium strains as active ingredients. In this study, a field experiment was conducted on two bioclimatic zones in South Africa during the 2019/2020 season to assess the effect of Bradyrhizobium japonicum strain WB74 inoculant formulation on nitrogen fixation, growth and yield improvement in soybeans. The first bioclimatic zone was characterized by a sandy clay loam soil, whereas the second bioclimatic zone has a sandy loam soil. The results showed that inoculation of soybeans with both peat and liquid formulations of Bradyrhizobium japonicum WB74 increased nitrogen uptake, which resulted in yield increase. The amount of N fixed was measured as 15N isotopes and increased with all treatments compared to the uninoculated control in both liquid and peat inoculant formulations. In bioclimatic zone A, slightly better results were obtained using the liquid formulation (1.79 t ha−1 for liquid compared to 1.75 t ha−1 for peat treatments), while peat formulations performed better in bioclimatic zone B (1.75 t ha−1 for peat compared to 1.71 t ha−1 for liquid treatments). In both areas higher yields were obtained with the formulations used in this study compared to the registered standards (treatment T3). The findings in this study provide vital information in the development and application of formulated microbial inoculants for sustainable agriculture in South Africa.
南非土壤普遍缺乏原生的缓生根瘤菌菌株，这些菌株在大豆(Glycine max L.)中结瘤并固定大气中的氮(N2)。因此，用含有有效缓生根瘤菌菌株作为活性成分的产品接种大豆是非常重要的。本研究于2019/2020年在南非的两个生物气气区进行了田间试验，评估了缓生日本根瘤菌WB74接种剂配方对大豆固氮、生长和增产的影响。第一生物气候带以砂质粘壤土为特征，第二生物气候带以砂质壤土为特征。结果表明，接种泥炭和液体配方的缓生根瘤菌WB74均能提高大豆的氮素吸收，从而提高产量。在液体和泥炭孕育剂配方中，与未接种对照相比，所有处理的固定N量都增加了。在生物气候区A，使用液体配方获得的效果略好(液体为1.79 t ha - 1，泥炭为1.75 t ha - 1)，而泥炭配方在生物气候区B表现更好(泥炭为1.75 t ha - 1，液体为1.71 t ha - 1)。在这两个地区，与注册标准(处理T3)相比，本研究中使用的配方获得了更高的产量。本研究结果为南非可持续农业配方微生物接种剂的开发和应用提供了重要信息。
{"title":"Efficacy of Peat and Liquid Inoculant Formulations of Bradyrhizobium japonicum Strain WB74 on Growth, Yield and Nitrogen Concentration of Soybean (Glycine max L.)","authors":"Auges Gatabazi, B. Vorster, Mireille Asanzi Mvondo-She, E. Mangwende, Robert Mangani, A. Hassen","doi":"10.3390/nitrogen2030023","DOIUrl":"https://doi.org/10.3390/nitrogen2030023","url":null,"abstract":"South African soils generally lack native Bradyrhizobium strains that nodulate and fix atmospheric nitrogen (N2) in soybeans (Glycine max L.). It is therefore very important to inoculate soybeans with products that contain effective Bradyrhizobium strains as active ingredients. In this study, a field experiment was conducted on two bioclimatic zones in South Africa during the 2019/2020 season to assess the effect of Bradyrhizobium japonicum strain WB74 inoculant formulation on nitrogen fixation, growth and yield improvement in soybeans. The first bioclimatic zone was characterized by a sandy clay loam soil, whereas the second bioclimatic zone has a sandy loam soil. The results showed that inoculation of soybeans with both peat and liquid formulations of Bradyrhizobium japonicum WB74 increased nitrogen uptake, which resulted in yield increase. The amount of N fixed was measured as 15N isotopes and increased with all treatments compared to the uninoculated control in both liquid and peat inoculant formulations. In bioclimatic zone A, slightly better results were obtained using the liquid formulation (1.79 t ha−1 for liquid compared to 1.75 t ha−1 for peat treatments), while peat formulations performed better in bioclimatic zone B (1.75 t ha−1 for peat compared to 1.71 t ha−1 for liquid treatments). In both areas higher yields were obtained with the formulations used in this study compared to the registered standards (treatment T3). The findings in this study provide vital information in the development and application of formulated microbial inoculants for sustainable agriculture in South Africa.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83576514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Synthetic nitrogen fertilizer use comes with unsustainable financial and environmental costs, making it not attractive to small-scale and organic farmers. Poultry manure (PM) when available is a primary fertilizer source for small-scale and organic farmers but there is still limited research on its effects of specific crops and soil fertility under specific practices. The study investigated PM effects on garden egg in three seasons in Ghana and PM effects soil fertility in sandy-loam soils of Arizona after three years under flood irrigation and no-till. The PM application improved garden egg growth (dry matter by 73%) and increased yield by 66% in slightly acidic sandy-loam tropical soils, which could be related to soil mineral improvement. In the semi-arid soil, three years PM application increased cation exchange capacity (41%), P (471%), K (18%), S (244%), Ca (45%), Mg (31%), Zn (5%) and Mn (19%) with reduction in nitrate (−26%), Fe (−38%) and Cu (−11%). The reduction in the nitrate and Fe in the semi-arid Arizona cropland could be associated to flood irrigation and high soil pH, respectively. To gain the full potential from PM applications, best management practice is recommended to reduce nitrate leaching.
{"title":"Poultry Manure Induced Garden Eggs Yield and Soil Fertility in Tropical and Semi-Arid Sandy-Loam Soils","authors":"I. K. Mpanga, E. Adjei, H. Dapaah, K. G. Santo","doi":"10.3390/NITROGEN2030022","DOIUrl":"https://doi.org/10.3390/NITROGEN2030022","url":null,"abstract":"Synthetic nitrogen fertilizer use comes with unsustainable financial and environmental costs, making it not attractive to small-scale and organic farmers. Poultry manure (PM) when available is a primary fertilizer source for small-scale and organic farmers but there is still limited research on its effects of specific crops and soil fertility under specific practices. The study investigated PM effects on garden egg in three seasons in Ghana and PM effects soil fertility in sandy-loam soils of Arizona after three years under flood irrigation and no-till. The PM application improved garden egg growth (dry matter by 73%) and increased yield by 66% in slightly acidic sandy-loam tropical soils, which could be related to soil mineral improvement. In the semi-arid soil, three years PM application increased cation exchange capacity (41%), P (471%), K (18%), S (244%), Ca (45%), Mg (31%), Zn (5%) and Mn (19%) with reduction in nitrate (−26%), Fe (−38%) and Cu (−11%). The reduction in the nitrate and Fe in the semi-arid Arizona cropland could be associated to flood irrigation and high soil pH, respectively. To gain the full potential from PM applications, best management practice is recommended to reduce nitrate leaching.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83652601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Environmental pollution is a major threat to public health and is the cause of important economic losses worldwide. Atmospheric nitrogen deposition is one of the most significant components of environmental pollution, which, in addition to being a health risk, is one of the leading drivers of global biodiversity loss. However, monitoring pollution is not possible in many regions of the world because the instrumentation, deployment, operation, and maintenance of automated systems is onerous. An affordable alternative is the use of biomonitors, naturally occurring or transplanted organisms that respond to environmental pollution with a consistent and measurable ecophysiological response. This policy brief advocates for the use of biomonitors of atmospheric nitrogen deposition. Descriptions of the biological and monitoring particularities of commonly utilized biomonitor lichens, bryophytes, vascular epiphytes, herbs, and woody plants, are followed by a discussion of the principal ecophysiological parameters that have been shown to respond to the different nitrogen emissions and their rate of deposition.
{"title":"Selecting Biomonitors of Atmospheric Nitrogen Deposition: Guidelines for Practitioners and Decision Makers","authors":"D. Martínez, E. A. Díaz-Álvarez, E. de la Barrera","doi":"10.3390/NITROGEN2030021","DOIUrl":"https://doi.org/10.3390/NITROGEN2030021","url":null,"abstract":"Environmental pollution is a major threat to public health and is the cause of important economic losses worldwide. Atmospheric nitrogen deposition is one of the most significant components of environmental pollution, which, in addition to being a health risk, is one of the leading drivers of global biodiversity loss. However, monitoring pollution is not possible in many regions of the world because the instrumentation, deployment, operation, and maintenance of automated systems is onerous. An affordable alternative is the use of biomonitors, naturally occurring or transplanted organisms that respond to environmental pollution with a consistent and measurable ecophysiological response. This policy brief advocates for the use of biomonitors of atmospheric nitrogen deposition. Descriptions of the biological and monitoring particularities of commonly utilized biomonitor lichens, bryophytes, vascular epiphytes, herbs, and woody plants, are followed by a discussion of the principal ecophysiological parameters that have been shown to respond to the different nitrogen emissions and their rate of deposition.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87685345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.20944/PREPRINTS202107.0006.V1
Taisiya Ya. Vorobyeva, A. Chupakova, A. Chupakov, S. Zabelina, O. Moreva, O. Pokrovsky
In order to better understand the biogeochemical cycle of nitrogen in meromictic lakes, which can serve as a model for past aquatic environments, we measured dissolved concentrations of nitrate, nitrite, ammonium and organic nitrogen in deep (39 m maximal depth) subarctic Lake Svetloe (NW Russia). The lake is a rare type of freshwater meromictic water boy with high concentrations of methane, ferrous iron, manganese and low concentrations of sulfates and sulfides in the monimolimnion. In the oligotrophic mixolimnion, the concentration of mineral forms of nitrogen decreased in summer compared to winter, likely due to phytoplankton bloom. The decomposition of the bulk of organic matter occurs under microaerophilic/anaerobic conditions of the chemocline and accompanied by the accumulation of nitrogen in the form of N-NH4 in the monimonimlion. We revealed a strong relationship between methane and nitrogen cycles in the chemocline and monimolimnion horizons. The nitrate concentrations in Lake Svetloe varied in the range from 9 to 13 μM throughout the water column. This fact is rare for meromictic lakes, where nitrate concentrations up to 13 µM are found in the monimolimnion zone down to the bottom layers. We hypothesize, in accord with available data for other stratified lakes, that under conditions of high concentrations of manganese and ammonium at the boundary of redox conditions and below, anaerobic nitrification with the formation of nitrates occurs. Overall, most of organic matter in Lake Svetloe undergoes biodegradation essentially under microaerophilic/anaerobic conditions of the chemocline and the monimolimnion. Consequently, the manifestation of the biogeochemical nitrogen cycle is expressed in these horizons in the most vivid and complex relationship with other cycles of elements.
{"title":"Distribution of Dissolved Nitrogen Compounds in the Water Column of a Meromictic Subarctic Lake","authors":"Taisiya Ya. Vorobyeva, A. Chupakova, A. Chupakov, S. Zabelina, O. Moreva, O. Pokrovsky","doi":"10.20944/PREPRINTS202107.0006.V1","DOIUrl":"https://doi.org/10.20944/PREPRINTS202107.0006.V1","url":null,"abstract":"In order to better understand the biogeochemical cycle of nitrogen in meromictic lakes, which can serve as a model for past aquatic environments, we measured dissolved concentrations of nitrate, nitrite, ammonium and organic nitrogen in deep (39 m maximal depth) subarctic Lake Svetloe (NW Russia). The lake is a rare type of freshwater meromictic water boy with high concentrations of methane, ferrous iron, manganese and low concentrations of sulfates and sulfides in the monimolimnion. In the oligotrophic mixolimnion, the concentration of mineral forms of nitrogen decreased in summer compared to winter, likely due to phytoplankton bloom. The decomposition of the bulk of organic matter occurs under microaerophilic/anaerobic conditions of the chemocline and accompanied by the accumulation of nitrogen in the form of N-NH4 in the monimonimlion. We revealed a strong relationship between methane and nitrogen cycles in the chemocline and monimolimnion horizons. The nitrate concentrations in Lake Svetloe varied in the range from 9 to 13 μM throughout the water column. This fact is rare for meromictic lakes, where nitrate concentrations up to 13 µM are found in the monimolimnion zone down to the bottom layers. We hypothesize, in accord with available data for other stratified lakes, that under conditions of high concentrations of manganese and ammonium at the boundary of redox conditions and below, anaerobic nitrification with the formation of nitrates occurs. Overall, most of organic matter in Lake Svetloe undergoes biodegradation essentially under microaerophilic/anaerobic conditions of the chemocline and the monimolimnion. Consequently, the manifestation of the biogeochemical nitrogen cycle is expressed in these horizons in the most vivid and complex relationship with other cycles of elements.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79280764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nitrogen fertilizer recommendations for corn (Zea mays L.) should ensure high yields using adequate N doses. Soil–plant analysis development (SPAD) meter technology using absolute SPAD values, might be more reliable than relative SPAD values in helping corn producers making timely decisions about N applications. This study aimed to develop a relationship between absolute SPAD values and leaf N concentration, and to determine optimal leaf N concentrations at early corn growth stages (V6, V8, V10, and V12). Three experiments were conducted during two summer seasons (2014 and 2015) using six N treatments applied at early corn growth stages. In parallel, two experiments were carried out in a high residual N environment to establish the optimum corn leaf N concentration. Results showed a significant linear relationship between corn leaf N concentrations and absolute SPAD values (R2 = 0.80, p < 0.05). The mean optimum corn leaf N concentration decreased over corn growth stages. It is of great importance to make the absolute SPAD method accessible for farmers, but more research is required to perform standardized reading of absolute SPAD values data.
玉米(Zea mays L.)的氮肥推荐量应确保使用足够的氮量获得高产。利用绝对SPAD值的土壤-植物分析发展(SPAD)测量技术，可能比相对SPAD值更可靠地帮助玉米生产者及时决策氮素施用。本研究旨在建立SPAD绝对值与叶片N浓度之间的关系，并确定玉米生长早期(V6、V8、V10和V12)的最佳叶片N浓度。试验分2014年和2015年两个夏季，在玉米生育期早期施用6种氮肥。同时，在高残氮环境下进行了两个试验，以确定玉米叶片氮的最佳浓度。结果表明，玉米叶片氮浓度与SPAD绝对值呈显著的线性关系(R2 = 0.80, p < 0.05)。随着玉米生育期的延长，玉米叶片平均最适氮浓度逐渐降低。使农民能够使用绝对SPAD方法是非常重要的，但对绝对SPAD值数据进行标准化读取还需要更多的研究。
{"title":"Feasibility Study of Using Absolute SPAD Values for Standardized Evaluation of Corn Nitrogen Status","authors":"Abdelaziz Rhezali, A. Aissaoui","doi":"10.3390/nitrogen2030020","DOIUrl":"https://doi.org/10.3390/nitrogen2030020","url":null,"abstract":"Nitrogen fertilizer recommendations for corn (Zea mays L.) should ensure high yields using adequate N doses. Soil–plant analysis development (SPAD) meter technology using absolute SPAD values, might be more reliable than relative SPAD values in helping corn producers making timely decisions about N applications. This study aimed to develop a relationship between absolute SPAD values and leaf N concentration, and to determine optimal leaf N concentrations at early corn growth stages (V6, V8, V10, and V12). Three experiments were conducted during two summer seasons (2014 and 2015) using six N treatments applied at early corn growth stages. In parallel, two experiments were carried out in a high residual N environment to establish the optimum corn leaf N concentration. Results showed a significant linear relationship between corn leaf N concentrations and absolute SPAD values (R2 = 0.80, p < 0.05). The mean optimum corn leaf N concentration decreased over corn growth stages. It is of great importance to make the absolute SPAD method accessible for farmers, but more research is required to perform standardized reading of absolute SPAD values data.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75910863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aluminum sulphate (alum, Al2(SO4)3·nH2O) has successfully been used to reduce ammonia loss from poultry litter, cattle feedlots and manure composting, but has not yet been utilized in the thermal drying process of digestate solids. The objectives of the present study were to evaluate the effects of alum addition on ammonium nitrogen (NH4+-N) content and phosphorus (P) solubility in dried digestate solids in comparison to the addition of concentrated sulfuric acid (H2SO4). Manure-based (MDS) and sewage sludge-based (SDS) digestate solids were chosen to conduct a drying experiment at four pH levels (original pH, 8.0, 7.5 and 6.5) and using two acidifying agents (alum, concentrated H2SO4). Alum addition increased the final NH4+-N content significantly from 1.4 mg g−1 in the non-acidified control up to 18 mg g−1 and 10.8 mg g−1 in dried MDS and SDS, respectively, which were higher levels than obtained with the addition of concentrated H2SO4. Moreover, alum considerably lowered the water extractable phosphorus (WEP) in raw and dried SDS by 37–83% and 48–72%, respectively, compared with the non-treated control. In contrast, concentrated H2SO4 notably increased WEP in raw and dried MDS by 18–103% and 29–225%, respectively. The comparison between the two acidifying agents indicated that alum had the potential to be an efficient and easy-handling alternative to concentrated sulfuric acid, resulting in higher NH4+-N content and lower P solubility.
硫酸铝(明矾，Al2(SO4)3·nH2O)已成功用于减少家禽垃圾、牛饲养场和粪肥堆肥中的氨损失，但尚未用于消化固体的热干燥过程。本研究的目的是评价明矾添加对干消化固体中铵态氮(NH4+-N)含量和磷(P)溶解度的影响，并与添加浓硫酸(H2SO4)进行比较。选取粪肥基(MDS)和污水污泥基(SDS)消化固体，在4种pH水平(原始pH、8.0、7.5和6.5)和2种酸化剂(明矾、浓硫酸)下进行干燥实验。明矾显著提高了未酸化对照的最终NH4+-N含量，从未酸化对照的1.4 mg g - 1提高到干燥MDS和SDS的18 mg g - 1和10.8 mg g - 1，高于添加浓H2SO4时的水平。与未处理的对照相比，明矾显著降低了生SDS和干SDS的水萃取磷(WEP)，分别降低了37-83%和48-72%。相比之下，高浓度H2SO4显著提高了生MDS和干MDS的WEP，分别提高了18-103%和29-225%。两种酸化剂的比较表明，明矾有潜力成为一种高效且易于处理的浓硫酸替代品，其NH4+-N含量较高，P溶解度较低。
{"title":"Comparison of Alum and Sulfuric Acid to Retain and Increase the Ammonium Content of Digestate Solids during Thermal Drying","authors":"Jingna Liu, L. S. Jensen, D. Müller-Stöver","doi":"10.3390/NITROGEN2020019","DOIUrl":"https://doi.org/10.3390/NITROGEN2020019","url":null,"abstract":"Aluminum sulphate (alum, Al2(SO4)3·nH2O) has successfully been used to reduce ammonia loss from poultry litter, cattle feedlots and manure composting, but has not yet been utilized in the thermal drying process of digestate solids. The objectives of the present study were to evaluate the effects of alum addition on ammonium nitrogen (NH4+-N) content and phosphorus (P) solubility in dried digestate solids in comparison to the addition of concentrated sulfuric acid (H2SO4). Manure-based (MDS) and sewage sludge-based (SDS) digestate solids were chosen to conduct a drying experiment at four pH levels (original pH, 8.0, 7.5 and 6.5) and using two acidifying agents (alum, concentrated H2SO4). Alum addition increased the final NH4+-N content significantly from 1.4 mg g−1 in the non-acidified control up to 18 mg g−1 and 10.8 mg g−1 in dried MDS and SDS, respectively, which were higher levels than obtained with the addition of concentrated H2SO4. Moreover, alum considerably lowered the water extractable phosphorus (WEP) in raw and dried SDS by 37–83% and 48–72%, respectively, compared with the non-treated control. In contrast, concentrated H2SO4 notably increased WEP in raw and dried MDS by 18–103% and 29–225%, respectively. The comparison between the two acidifying agents indicated that alum had the potential to be an efficient and easy-handling alternative to concentrated sulfuric acid, resulting in higher NH4+-N content and lower P solubility.","PeriodicalId":19365,"journal":{"name":"Nitrogen","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72964328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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