No-till corn after bromegrass: Effect on soil carbon and soil aggregates
Follett, RF; Varvel, GE; Kimble, JM; Vogel, KP
| HERO ID | 5013404 |
|---|---|
| In Press | No |
| Year | 2009 |
| Title | No-till corn after bromegrass: Effect on soil carbon and soil aggregates |
| Authors | Follett, RF; Varvel, GE; Kimble, JM; Vogel, KP |
| Journal | Agronomy Journal |
| Volume | 101 |
| Issue | 2 |
| Page Numbers | 261-268 |
| Abstract | Grasslands in the Conservation Reserve Program (CRP) in the USA may be converted to grain crops for bioenergy. The effect of no-till conversion of a smooth bromegrass (Bromus inermis Leyss) grassland to no-till corn (Zea mays L.) production on soil organic carbon (SOC) in the western Corn Belt was monitored for over 6 yr. A different (13)C/(12)C isotope signature is imparted to SOC by C4 plants including corn versus C3 plants such as bromegrass. Changes in C isotope ratios in SOC in three soil depths (0- to 5-, 5-10, and 10-30 cm) by particle size was also monitored during similar to 6.5 yr of no-till corn production at two different N levels (60 and 120 kg ha(-1)). Soil was collected eight times during the study from the 0- to 5- and 5- to 10-cm depths, and at four of these times from the 10- to 30-cm depth from each of the N rate replicates. Because fertilizer N had no significant effect over years on any of the aboveground biomass production variables, the data from both N treatments was combined for regression analysis to determine the effects of years of no-till corn production on SOC variables. Total SOC did not change significantly at any depth during the study, but there was a significant change in the source of the SOC. Total C4-C increased over this time, while C3-C decreased in the 0- to 5- and 5- to 10-cm depth, while neither changed in the 10- to 30-cm depth. In the 0- to 5- and 5- to 10-cm depths, largest loss of C3-C was from 2-mm aggregates, while largest increases in C4-C were in the 1-, 0.5-, 0.25-, and 0.125-mm aggregates. If CRP grasslands are converted to grain crop production, the data from this study strongly support the use of no-till farming practices as a method of conserving the SOC that was sequestered during the time period that the land was in the CRP. |
| Doi | 10.2134/agronj2008.0107 |
| Wosid | WOS:000266374400003 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |