Genotype influences survival and growth of eastern cottonwood (Populus deltoides L.) managed as a bioenergy feedstock on retired agricultural sites of the Lower Mississippi Alluvial Valley

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• 作者：K. C. Dipesh ; Michael A. Blazier ; Matthew H. Pelkki ; Hal O. Liechty
• 关键词：Eastern cottonwood ; LMAV ; Marginal sites ; Genotypes ; Cropping systems
• 刊名：New Forests
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：48
• 期：1
• 页码：95-114
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Forestry;
• 出版者：Springer Netherlands
• ISSN：1573-5095
• 卷排序：48

文摘

The global community needs a sustainable and renewable sources of energy as alternatives to finite fossil fuels that are also associated with climate change. Eastern cottonwood (Populus deltoides Bartr.) is a fast-growing candidate for cultivation as a short-rotation woody crop for biofuel production and it is planted throughout Asia, Europe, and the Northern America. It is native to the Lower Mississippi Alluvial Valley (LMAV) of the South Central United States. The LMAV has climatic, edaphic, and infrastructural attributes conducive to biofuel production, but much of the most productive sites of the region are dedicated to agricultural production because it is the most economically prime use. To foster development of a biofuel industry of the region may require biomass production on sites suboptimal for agricultural production. In this study, cropping systems and genotypes for cottonwood production were tested at three retired agricultural sites in the LMAV, Archibald, Colt, and Rohwer. Cropping systems tested were monoculture and alley cropping systems with two different alley widths. Genotypes tested were clones from Mississippi (ST-66) and Texas (S7C20) and a mixture of clones from Louisiana (LAMIX). Several interactions among site, genotype, and cropping system treatments were detected in survival and growth parameters. By the end of the study period, survival ranged from 30 to 81%, while height and diameter at breast height (dbh) ranges were 3.12–5.78 m, and 2.09–4.39 cm, respectively. Overall, survival and growth performance in this study were low compared to previous studies, suggesting the difficulty of managing productive cottonwood plantations under the suboptimal site conditions tested. Pronounced droughts during half of the years in this study and poor soil conditions were likely the primary reasons behind such performance of the genotypes. The study found no effect of cropping systems on individual tree growth. Genotypes from Texas and Louisiana showed relatively better survival (P = 0.0029) and growth (P < 0.001 to P = 0.0207) than the clone from Mississippi in the site conditions tested. Among sites, Rohwer, which had deep clay soil, had the highest biomass production (8299 kg ha−1). Survival and growth was limited at the Archibald site by ponding of water in winter and early spring in the establishment year and 2 years of pronounced drought in following years. A greater recurrence of competing vegetation at Archibald likely contributed to its lower survival (30%) and growth (biomass ranging from 1026 to 1511 kg ha−1 among the treatments) by the end of the study period. We suggest selecting drought-hardy genotypes along with site preparation and fertilization in such marginal sites.