|Sainju, U - FORT VALLEY STATE UNIV.|
|Singn, B - FORT VALLEY STATE UNIV.|
|Rahman, S - FORT VALLEY STATE UNIV.|
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 3, 1999
Publication Date: N/A
Interpretive Summary: A three year study was conducted to evaluate tomato root growth as influenced by tillage, cover cropping, and nitrogen fertilization. The results showed root proliferation from 6.5 to 19.5 cm was greatest with no-till with hairy vetch (HV) or with 0 kg N/ha, probably due to increased soil moisture conservation and/or nitrogen availability from HV residue. The moldboard plowing (MP) plus 180 kg N/ha increased root proliferation only at a depth greater than 26.0 cm, probably due to less soil impedance and/or increased N availability from soil N mineralization or N fertilization. The total number of roots between 1 and 58.5 cm was not influenced by management practices, but increased rapidly with date of measurement because of increased temperature. Therefore, no-till (NT) with HV cover cropping is beneficial for promoting tomato root development. It increases water and nutrient uptake and shoot anchorage better than MP with or without hairy vetch (HV) cover cropping and MP with or without N fertilization.
Technical Abstract: The influence of tillage [no-till(NT) vs. moldboard plowing(MP)], cover crop [hairy vetch(Vicia villosa Roth)(HV) vs. no hairy vetch(NHV)], and N fertilization (0 and 180 kg N/ha) on root distribution and growth rate of tomato (Lycopersicon esculentum Mill) transplants was examined in the field from May to August in 1996 and 1997. Experiments were conducted on a Norfolk sandy loam (fine-loamy, siliceous, thermic, Typic Kandiudults) in central Georgia. Root growth was estimated every 1-2 weeks with minirhizotron tubes installed in the plot. Roots were well distributed at soil depths between 1 and 58.5 cm. A maximum root count of 3.14 roots/cm2 soil profile area was found at 19.5 cm depth with MP and no N fertilization in 1996. In general, NT with HV or with 0 kg N/ha increased root proliferation at a depth of 6.5 to 19.5 cm, while MP with 180 kg N/ha increased root proliferation at greater depths. Total root count between 1 and 58.5 cm was not influenced by management practices but increased linearly at rates of 0.35 roots/cm2/d from 20 June to 11 July 1996 and 0.03 roots/cm2/d from 16 May to 5 August 1997. Root growth thereafter was minimal due to the higher temperature during early development. Growth rate and number of roots were greater in 1996 than in 1997. Superior moisture conservation, accompanied by increased N availability, may have increased root proliferation in the surface soil in NT with HV or with 0 kg N/ha compared to NT with NHV or with 180 kg N/ha and MP with or without HV or with or without N fertilization. Root growth, however, was not related with tomato yield.