1 Plant Archives Vol. 20, Supplement 2, 2020 pp. 292-296 e-ISSN:2581-6063 (online), ISSN:0972-5210 RESPONSE OF TOMATO LYCOPERSICON ESCUIENTUM MILL. AND SOIL MICROBIAL ACTIVITY TO GLOMUS MOSSEAE, TRICHODERMA HARZIANUM AND CHEMICAL FERTILIZATION Salwan Al-Maliki and Hendrin Al-Helou Soil and Water Resources Department, College of Agriculture, Al Qasim Green University, Iraq Corresponding author: salwan.mohammed@yahoo.com, adelhendreen@gmail.com Abstract Mycorrhizal fungi, Trichoderma and chemical fertilizer have a desirable affect on tomato yield. However, the concern to eliminate the chemical fertilization and depends on microbes inoculations is still clouded. A field experiment was carried out into greenhouses in the Al- Seyahi area, Babil Governorate to find out the role of bio- fertilization and chemical fertilizers on increasing microbial activity and tomato productivity. The split-plot design was used with three replicates, where the main plot included chemical fertilization 0%, 50% and 100% of the recommended doses. The subplot was included four types of bio-fertilization, control (C), Mycorrhizal (M), Trichoderma (T) and the mixture between Mycorrhizal fungi and Trichoderma (MT). Results showed that there was a significant increase in the microbial activity, bacterial and fungal cell numbers, nitrogen and phosphorus content and the total yield at the 100% and 50% of the recommended doses. Moreover, M led to a significant increase in the number of bacteria (41.7 x 10 -6 colony-forming unit CFU g dry soil), and Mycorrhizal infection rate (80.02%). In addition, in MT treatment, the percentage of organic carbon increased by 0.39%, and the number of fungal cells were significantly higher than others (22.4 x 10 -3 CFU g dry soil). The highest total yield was at MT (121.667 t.ha -3 ). In conclusion, the combination of Mycorrhizal fungi with Trichoderma at 50% of the recommended doses increased the total yield (151.67 ton. ha -1 ) and consequences on the reduction of soil contamination. Keywords: tomato Lycopersicon escuientum Mill, Mycorrhizal (Glomus mosseae), Trichoderma (Trichoderma harzianum), microbial activity, nutrients. Introduction The Lycopersicon escuientum Mill. (Tomato) belongs to the Solanaceae family. It is a widespread crop that is consumed in large quantities and is important because of the higher nutritional value, carbohydrates, proteins, organic acids and minerals such as potassium, phosphorus, and iron as well as antioxidants (Gol, 2006). However, Fertilization with its various chemical types plays an important role in improving plant growth and increasing productivity, but the high prices of chemical fertilizers and its toxic influence have become a real burden. Furthermore, Iraqis soils are suffered from the low organic matter and higher salinity (AL-Maliki et al., 2018; Al-maliki 2016; AL-maliki et al., 2019; AL- maliki et al., 2014). Therefore, the urgent need to use alternatives that contribute to reducing the use of chemical fertilizers and enhance soil organic matter is an ultimate priority. Biofertilizers were among the most important alternatives tool, including fungus and bacterial inoculations, which play an important role in increasing organic matter decomposition, absorption of nutrients, as well as, hormones production (Kumar et al., 2013; Mathur, 2018). In contrast, an excessive use of chemical fertilizers may cause environmental damages particularly to groundwater. Therefore, the use of biofertilizers is one of the most successful solutions to coping with these pollutants. Mycorrhizal Fungus can contribute to the growth and productivity of tomato by improving the roots density, increasing the nutrient absorption and plant resistance to disease infections (Kumar et al., 2013). Mycorrhizal Fungus can enhance aggregation, infection rate, microbe’s numbers as well as potato yield (AL-Maliki and AL-masswdy 2018; AL-Maliki and AL- Zabee 2019) Moreover, Trichoderma is quite beneficial for plant growth (Zhang et al., 2016). The proposed hypothesis is that Mycorrhizal Fungus and Trichoderma might be used as an alternative choice for the chemical fertilizer. Therefore, the study aims was to find out the effect of both Mycorrhizal fungi and Trichoderma fungi on the microbial activity, productivity of tomato and also attempting to reduce the fertilizer recommendation of tomato. Materials and Methods A field experiment was carried out in the Al-Seyahi area - Al-Husain Village - Babil Governorate (32 39 '33.54 "N and E 44 55' 09. 62”) in 2019. The experiment was designed according to the Randomized complete block design R.C.B.D. The arrangement of split-plot with three replicates was designed (Sahuki and Waheeb, 1990). The main plot included chemical fertilization at three levels (zero, 50% and 100%) of the chemical fertilizer recommendation of tomato. While for the subplot; it was included four types of bio fertilization, (comparison without the addition (C), Mycorrhizal (M), Trichoderma (T) and the mixture between Mycorrhizal and Trichoderma (MT). Soil preparations were conducted included plowing and leveling. The study area was divided into three blocks; each block contained 12 plots. The area of experimental unit was 4 m 2 (2 * 2) in a dimensions. Two meter distance was left between the blocks and 1 m distance was also left between the experimental units to prevent the leaking of the soil chemical fertilizers to the non- aimed samples. Furthermore, the experiment was fertilized according to the approved recommendations at a rate of 200 kg nitrogen (N46%), 60 kg of concentrated calcium superphosphate (p 20%) and 120 kg of potassium sulfate (41.5% k) (Faraj, 2009). Field soil samples were taken from a depth of (0-30) cm in order to analyze particular soil properties as shown in Table 1. The irrigation process was carried out using the drip irrigation system, as the water flow was 75 ml per minute. The following parameters were studied; including the microbial activity according to (Anderson, 1982; AL-Maliki et al., 2017), bacteria and fungi numbers was estimated according to (Stotzky et al., 1993). In