Title: Intercropping with Kura Clover Improves Soil Quality in a Pecan Agroforestry System Authors
|Kussman, Robert - FARMER|
Submitted to: Soil and Water Conservation Society
Publication Type: Abstract Only
Publication Acceptance Date: July 12, 2008
Publication Date: July 26, 2008
Citation: Kremer, R.J., Kussman, R. 2008. Intercropping with Kura Clover Improves Soil Quality in a Pecan Agroforestry System [abstract]. SWCS Meeting Abstracts. Soil and Water Conservation Society Annual Meeting. July 26-30, 2008, Tuscan, AZ. Available: http://www.swcs.org/08ac. Technical Abstract: Intercropping the alleys of agroforestry systems provides income until the tree crop begins to yield. However, cultivation of annual crops or intensive herbicidal control of vegetation in the alleys decreases soil organic matter and increases soil erosion, especially on sloping landscapes. Perennial crops maintain a continuous soil cover, maximize water infiltration, minimize soil erosion, and improve overall soil quality. The objective of this on-farm study was to assess the effects of a perennial legume, kura clover (Trifolium ambiguum), on various soil quality parameters in a recently established pecan (Carya illinoinensis) plantation. The pecan-kura clover agroforestry system was established on the Kussman Pecan & Cattle Farm in Chariton County, Missouri on deep loess soils of the Menfro-Higginsville-Wakenda association (Argiudolls and Hapludalfs). These silt loams are on 3 to 10% slopes and are subject to erosion. Kura clover was intercropped in the eight-year-old pecan plantation to take advantage of its perennial growth habit, nitrogen-fixing ability, winter hardiness, high quality forage, and soil conservation properties. Kura clover was seeded in 2002 and has been harvested for hay annually since 2003. During this period soil organic matter and activities of soil enzymes (dehydrogenase, glucosidase, glucosaminidase) have steadily increased compared with cultivated and grass pasture control soils. Water-stable aggregation improved by 50% during this period. Results to date illustrate that kura clover, as the interplanted component, improved soil fertility and biological activity through increased organic matter and improved soil structure (increased soil aggregation), and yielded a high quality forage valuable for the cattle-feeding operation. Pecan trees thrive in this system partly because soil quality is maintained or improved and, unlike other “living mulch” systems in which cover crops may suppress the main crop, kura clover does not compete with tree growth.