<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "Increased proportion of active soil N in Breton loam under cropping systems with forages and green manures"^^ . "Total soil N and N mineralization\r\nrate partially ctririct&iie the influence olvariouJcropping systems on the growth of.sequent.crop.s in a rotation' The objectives\r\nof this study were to (1) quantify the relationship among cropping system, total N and mineralizable N, and (2) compare amount\r\nof N mineralized under'controlled laboratory conditions-with pianl N uptake under green]ouse conditi:ns. Three cropping systems\r\nthat have been in operation between 9 and 60 yr on a Gray-Luvisol (Breton loam; were\r\n^selected . They included: (1) an ag.lo:\r\necological (lnn) d-yr rotation involving fabibeans as gr-een manure (AER1 sampled after the_first lababean crop-?nq AER?\r\n,u-pied after 3 yr of continuous forage)l (2) continuous grain system (CG), with fertilizer N at 90 kg ha-'^yr- '; inttrated\r\nin 1980 and considered established in f\"98i; i3) a classicial Ereton iotation (CBR) involving 9]o-ng-term (ca. 1930) 5-yr rotation\r\nwith forages and cereals and no return of.ciop residues (CBR1 fertilized with P-K-S and CBR2 unfertilized). We cautio_n that\r\nnot all ohlses of each rotation were sampled: bur conclusions pertain to N-mineralization potential in soil samples immediately\r\npreceding barley as sequent crop in each rotation. The rate ofN mineralization declined with time, but it remained greater than\r\niero aftei 20 wi< of incirbation in all soils. Mineral-N accumulation at 20 wk followed the order AER1 > AER2 > > CBRI >\r\nCBR2 : CG. Mineralizable soil N, following one cycle of the AER rotation, was almost double that following 60 yr of the\r\nCBR rotation. Data for mineral-N accumulation under laboratory conditions were described best by a single-component expo-n-ential\r\nmodel. Legume-based rotations were associated with increased total soil N and a greater proportional increase in active N than\r\nin total soilN. Active N was least in soil under the CG system. The incubation-extraction procedure resulted in higher estimates\r\nof mineralizable N than did the plant-uptake method; liowever, the ranking of N-supplying power of soils was the same."^^ . "1994" . . "74" . "1" . . "Agricultural Institute of Canada"^^ . . . "Canadian Journal of Soil Science"^^ . . . "19181841" . . . . . . . . . . . . . . . . "W B"^^ . "McGill"^^ . "W B McGill"^^ . . "N G"^^ . "Juma"^^ . "N G Juma"^^ . . "K L"^^ . "Haugen-Kozyra"^^ . "K L Haugen-Kozyra"^^ . . "S P"^^ . "Wani"^^ . "S P Wani"^^ . . . . . . "Increased proportion of active soil N in Breton loam under cropping systems with forages and green manures (PDF)"^^ . . . . . . . . . . . "CandJouSoilSci74_1_67-74_1994.pdf"^^ . . . "Increased proportion of active soil N in Breton loam under cropping systems with forages and green manures (Image (JPEG))"^^ . . . . . . "Increased proportion of active soil N in Breton loam under cropping systems with forages and green manures (Indexer Terms)"^^ . . . . . "HTML Summary of #3559 \n\nIncreased proportion of active soil N in Breton loam under cropping systems with forages and green manures\n\n" . "text/html" . . . "Soil Science"@en . .