Effect of Biochar and Inorganic Fertilizers on Nitrogen and Phosphorus Uptake, Mycorrhizal Fungi Colonization, Growth and Yield of Tomato (Lycopersicon lycopersicon) at Jimma, South West Ethiopia

Abstract

Soil fertility management practices are the most important factors that affect tomato growth and its productivity on wide range of soil types. Tomato production in South west Ethiopia concentrates mainly on acidic soils where Nitrogen and Phosphorus nutrients are limiting. Biochar is one of the most important and easily available soil amendment resources that can improve soil conditions and help plant root access to mycorrhizal fungi thereby improve nitrogen and phosphorus nutrition of the plant. However, there are still many uncertainties about biochar, particularly in terms of making sure that it has positive effects with a particular soil and crop type. An experiment was therefore, conducted to determine the effect of biochar integrated with inorganic fertilizer application on Nitrogen and Phosphorus uptake and arbuscular mycorrhizal fungi (AMF) root colonization by tomato. The experiment was conducted under greenhouse conditions from January 2016 to may 2016.The experiment was laid out as randomized complete block design and replicted four times. The experiment consisted of five levels of biochar application (0, 6, 12, 36, and 72t/ ha) that were integrated with chemical fertilizers. Data on growth and yield parameters, AMF colonization, and Nitrogen and Phosphorus uptake were collected and statistically analyzed using SAS version9.2 software. Analysis of variance showed that application of biochar significantly (P<0.05) affected all the studied parameters. Application of 36 t/ha biochar supplemented with 96 N and 92 P2O5 kg/ha showed a significant increase in all growth and yield parameters. Moreover, Nitrogen uptake showed improvment by haulm (1.4gm/plant), fruit (7.47gm/plant) and total plant uptakes (8.87gm/plant) and P uptake by haulm (1.4gm/plant), fruit (4.9gm/plant) and total plant (6.2gm/plant) were also improved at 36 t/ha biochar supplemented with 96 N and 92 P2O5 kg/ha. On the other hand, tomato roots showed significant (P<0.05) mycorrhizal association with typical fungi structures (arbuscules, hyphae and vesicles). The height hyphae (HC) colonization (76.9%) was found from 72 ton biochar alone. However, significantly lower HC colonization (13%) was recorded from the control. Moreover, significant and positive correlation was also observed between total N and P uptake with number of fruit and mycorrhizae hyphal colonization (AMF). In conclusion, application of 36t/ha biochar supplemented with 96 N and 92 P2O5 kg/ha was found to give highest N and p uptake and better fruit tomato yield. Therfore, extending the experiment to a field-scale is suggested in order to test whether the pot-trial results can be reproduced or not