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| Registros recuperados: 20 | |
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| FERNANDES, J. A. B.; CARVALHO, F. C. de; ARAUJO FILHO, J. A. de; CAMPANHA, M. M.; DUTRA, L. A.. |
| Resumos: A manta orgânica é resultado da queda e acumulação do litter, material vegetal que cai no solo em um ambiente florestal. Este processo é de fundamental importância para a circulação dos elementos minerais dentro do ecossistema. Durante a decomposição da manta orgânica ocorre liberação dos nutrientes minerais contidos nesta, tornando-os disponíveis, no meio edáfico, para a vegetação.Objetivou-se quantificar a queda e deposição do Litter e manta orgânica e avaliar a ciclagem de N a partir dos mesmos, em um sistema agrossilvipastoril. Conduzido no período de agosto de 2001 a julho de 2002, na Embrapa Caprinos, Sobral-CE, com médias pluviométricas de 1002,5 e 905,3 mm respectivamente. Foram avaliados três tratamentos no sistema agrossilvipastoril... |
| Tipo: Anais e Proceedings de eventos |
Palavras-chave: Sistema agrossilvipastoril; Ciclagem de nutriente; Manta orgânica; Código florestal; Teor de nitrogênio; Brasil; Ceará; Sobral; Agrosilvopastoral systems.; Caatinga.; Nitrogen content; Brazil; Semiarid soils; Silvopastoral systems.. |
| Ano: 2008 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/534515 |
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| GROPPO, J. D.; LINS, S. R. M.; CAMARGO, P. B.; ASSAD, E. D.; PINTO, H. S.; MARTINS, S. C.; SALGADO, P. R.; EVANGELISTA, B.; VASCONCELLOS, E.; SANO, E. E.; PAVÃO, E.; LUNA, R.; MARTINELLI, L. A.. |
| Abstract. In this paper, soil carbon, nitrogen and phosphorus concentrations and stocks were investigated in agricultural and natural areas in 17 plot-level paired sites and in a regional survey encompassing more than 100 pasture soils In the paired sites, elemental soil concentrations and stocks were determined in native vegetation (forests and savannas), pastures and crop-livestock systems (CPSs). Nutrient stocks were calculated for the soil depth intervals 0-10, 0-30, and 0-60 cm for the paired sites and 0-10, and 0-30 cm for the pasture regional survey by sum stocks obtained in each sampling intervals (0-5, 5-10, 10-20, 20-30, 30-40, 40-60 cm). Overall, there were significant differences in soil element concentrations and ratios between different land... |
| Tipo: Artigo de periódico |
Palavras-chave: Nutrientes no solo; Estoque de nitrogênio; Estoque de carbono; Estoque de fósforo; Concentração de nitrogênio; Concentração de carbono; Concentração de fósforo; Estequiometria; Agricultura; Solo; Agriculture; Nitrogen content; Carbon sinks; Soil; Soil nutrient balance; Stoichiometry. |
| Ano: 2015 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1038618 |
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| San Juan Martínez, Erwin. |
| El diagnóstico oportuno del estado nutrimental de los cultivos en la agricultura de precisión es de suma importancia y vitalidad; por lo que cada vez se hacen más necesarias técnicas que permitan conocer el estado nutrimental del cultivo de forma rápida, precisa y confiable. Es por ello que el presente trabajo tuvo como objetivo determinar la concentración de nitrógeno foliar en chile de agua mediante reflectancia, dicha característica se obtuvo por medio de equipos como: radiómetro (CROPSCAN), escáner de escritorio y cámara fotográfica digital, de igual forma se determinó un índice de verdor utilizando el medidor portátil SPAD Minolta 502 y, la concentración de nitrógeno foliar por el método Kjeldahl. A partir de esas mediciones y con el programa Curve... |
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Palavras-chave: Agricultura de precisión; Firmas espectrales; Nutriente; Precision agriculture; Spectral signatures; Nitrogen content; Edafología; Maestría. |
| Ano: 2014 |
URL: http://hdl.handle.net/10521/2285 |
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| 申, 宝明; 佐藤, 禎稔; 加藤, 拓; 谷, 昌幸; 岸本, 正; SHEN, Baoming; SATOW, Tadatoshi; KATO, Taku; TANI, Masayuki; KISHIMOTO, Tadashi. |
| マニュアスプレッダで散布された堆肥の乾物質量と窒素投入量の圃場内分布を評価するために，３つの 圃場で散布試験を実施した。供試堆肥の含水率は平均で５３～８１％と圃場ごとに大きな差異が見られ，その 変動係数はB とC 圃場が４．６％以内であったのに対し，A 圃場は９．４％以上とばらつきが大きかった。バー ク堆肥の窒素含有量は牛ふん堆肥に比べると少なく，その平均はA 圃場で１４．７g／kg, C 圃場で１６．８g／kg であった。圃場全体の堆肥の散布量と窒素投入量の変動係数はいずれの圃場でも４９％以上とばらつきが大 きかった。しかし，堆肥の含水率の変動が少ない圃場では，堆肥の現物質量と窒素投入量の分布形状がほ ぼ一致することから，圃場内の窒素投入量を均一にするためには，堆肥水分のばらつきを少なくし，かつ 堆肥散布精度を向上させることが必要であると考える。 In order to evaluate distribution variability of the dry weight and the amount of nitrogen input of the compost applied with manure spreaders, the experiments of compost application were carried out in three fields. The mean values of compost moisture content at three experimental fields range from 53 to 81%, and their differences between three fields were significant. The... |
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Palavras-chave: 堆肥散布機; 散布量分布; 窒素含有量; バーク堆肥; 牛ふん堆肥; Manure spreader; Distribution map; Nitrogen content; Bark compost; Cattle compost. |
| Ano: 2011 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3067 |
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| Bagheri,Nikrooz; Ahmadi,Hojjat; Alavipanah,Seyed Kazem; Omid,Mahmoud. |
| The objective of this work was to evaluate the use of multispectral remote sensing for site-specific nitrogen fertilizer management. Satellite imagery from the advanced spaceborne thermal emission and reflection radiometer (Aster) was acquired in a 23 ha corn-planted area in Iran. For the collection of field samples, a total of 53 pixels were selected by systematic randomized sampling. The total nitrogen content in corn leaf tissues in these pixels was evaluated. To predict corn canopy nitrogen content, different vegetation indices, such as normalized difference vegetation index (NDVI), soil-adjusted vegetation index (Savi), optimized soil-adjusted vegetation index (Osavi), modified chlorophyll absorption ratio index 2 (MCARI2), and modified triangle... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aster; Nitrogen content; Near infrared; Multispectral response; Precision agriculture; Vegetation indices. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2013001000011 |
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| Liu,ZG; Cai,YL; Li,K. |
| Induced responses to herbivory are physical, nutritional, and allelochemical traits that change in plants following disturbances, and reduce the performance and/or preference of leaf tissues on herbivores. This study gave evidence to the induced defense theory through the simulated herbivory in Schima superba, one of common dominant trees in subtropical evergreen, broadleaf forests in southern China. Results showed that leaves damaged at the beginning of leaf expansion would develop into having a larger area, higher toughness and higher tannin concentrations, but a lower water content compared with control leaves. As a result, they experienced lower herbivory rates than controls. These results indicate that simulated herbivory on leaves of S. superba (1)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Induced response; Herbivory; Simulated herbivory; Nitrogen content; Schima superba. |
| Ano: 2010 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-56572010000100012 |
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| Morais,Léa P. V. X. C. de; Bonfim-Silva,Edna M.; Pacheco,Adriano B.; Abreu,Joadil G. de; Silva,Tonny J. A. da; Polizel,Analy C.. |
| ABSTRACT This study aimed to evaluate the production and mineral nutrition of Piatã grass as a function of nitrogen and potassium fertilization in Oxisol collected in the Cerrado. The experiment was carried out in a greenhouse, the experimental design was completely randomized, in a 5 x 5 factorial scheme, corresponding to five nitrogen doses (0, 100, 200, 300 and 400 mg dm-3 of N) and five potassium doses (0, 90, 180, 270 and 360 mg dm-3 of K2O), with four replicates. Three cuts of the shoots were performed every 30 days. Chlorophyll index, dry mass of shoots and roots, and nitrogen and potassium contents in the leaves were evaluated. The dry mass of shoots showed interaction between nitrogen and potassium in the three cuts; in the second and third cuts,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brachiaria brizantha; Nitrogen content; Potassium content; N:K ratio in plants. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016001100984 |
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| 楊純明; Chwen-Ming Yang. |
| [[abstract]]本文研究在行政院農委會農業試驗所農場（臺中縣霧峰鄉）進行，調查2000年二期稻作至2002年一期稻作（二年四期作）之水稻生育期間稻株葉片葉綠素總量與氮素含量及葉綠素測計讀值，分析葉綠素與氮素含量關係，再釐清是否可以利用葉綠素測計讀值估測葉綠素及氮素之變化，並比較期作間差異。根據試驗結果，發現葉片之葉綠素總量、氮素含量或葉綠素測計讀值均隨著稻株生育進展而呈現下降趨勢，此一表現不受本試驗不同等級氮肥施用量之影響。續將稻株葉片之氮素含量與葉綠素總量進行相關分析，發現一、二期稻作皆可以直線正相關表示兩變數的關係，且由於兩期稻作資料經虛擬變數檢定為不顯著，乃進一步將兩期作資料合併分析，兩變數之間仍為顯著直線正相關 (R2=0.615, P<0.0001)。又試驗分析亦顯示，稻株葉片之葉綠素總量與葉綠素測計讀值之關係十分密切，可適用於直線相關，一、二期稻作之決定係數 (R2) 分別為0.758及0.862。兩期作資料經虛擬變數檢定為不顯著，其合併分析亦顯示兩變數間為顯著直線正相關 (R2=0.784, P<0.0001)。基於前述二項分析，乃將葉片氮素含量與葉綠素測計讀值進行相關分析，發現兩者在統計上無論期作均為顯著直線正相關，一、二期稻作之決定係數分別為0.574及0.439，並且可以合併分析產生兩期稻作共用之迴歸方程式 (R2=0.411, P<0.0001)。綜合試驗結果，在本研究採用之水稻品種臺農67號，建議可以利用葉綠素測計讀值推估稻株葉片之葉綠素與氮素含量，此一功能在氮肥管理上具有應用意義。 |
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Palavras-chave: 水稻 葉綠素測計 葉綠素總量 氮素含量 氮肥管理 Rice; Chlorophyll meter; Total chlorophyll; Nitrogen content; Nitrogen fertilizer management [[classification]]6. |
| Ano: 2003 |
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| Somporn Kamyot. |
| The research objectives were to investigate green manure species namely Crotalaria juncia on yield, yield components and nitrogen content of rice cv. Sangyodphatthalung was conducted in paddy soil condition of Phatthalung Soil Series. The experimental design was RCBD of which consisted of 7 treatments by using different seed rates (kg rai-1) as compared to chemical fertilizer i.e. 0, 5, 10, 15, 20, 25 and 8-10-0 kg N-P2O5-K2O rai-1. The results of yield showed that significantly different with different seed rates, the treatment of 15, 20, 25 kg rai-1 and CF gave similar highest average yield (386.8, 388.9, 385.7, 409.5 kg rai-1 respectively) and highest average number of no. of panicle hill-1, no. of spikelet panicle-1 and % of filled grain whereas the N... |
| Tipo: Collection |
Palavras-chave: Rice; Sangyodphatthalung rice; Green manure; Yield; Yield component; Nitrogen content; ข้าว; พันธุ์สังข์หยดพัทลุง; ปอเทือง; ปุ๋ยพืชสด; ผลผลิต; องค์ประกอบผลผลิต; ปริมาณไนโตรเจน. |
| Ano: 2012 |
URL: http://anchan.lib.ku.ac.th/agnet/handle/001/5373 |
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| Registros recuperados: 20 | |
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