Sustainable Greenhouse Tomato Production: Benefits of Inoculation With Arbuscular Mycorrhizal Fungi Under Low Nitrogen and Phosphorus Conditions

The effects of overused chemical fertilizers, which threaten soil, plant, and human health, have always remained a topic of interest in theory and practice, emphasizing the judicious use of mineral nutrients. This study was aimed at reducing the harmful effects of excessive chemical fertilizer application and at exploring alternative approaches that can improve soil fertility without environmental and health damage. The experimental design involved a controlled greenhouse setup where tomato cultivars were inoculated with different AMF species under varying nitrogen (N) and phosphorus (P) doses. The tomato cultivars Rio Grande and Nadir were inoculated with arbuscular mycorrhizal fungi species, including <i>Glomus claroideum</i>, <i>Glomus etunicatum</i>, <i>Glomus fasciculatum</i>, and <i>Glomus mosseae</i>-within a commercial greenhouse. This study aimed to evaluate the potential effects of these fungi on tomato growth physiology, yield, and fruit quality when subjected to varying doses of N and <i>P. Glomus mosseae</i> significantly increased plant height by 14%, stem diameter by 22.25%, dry matter by 23.59%, yield by 38.57%, N uptake by 16.40%, P uptake by 37.5%, potassium (K) uptake by 18.55%, chlorophyll a (Chl a) content by 15.18%, and chlorophyll b (Chl b) content by 25.19% when compared to untreated controls. Additionally, <i>Glomus mosseae</i> improved fruit diameter by 9.98%, fruit firmness by 18.45%, juice content by 15.20%, titratable acidity (TA) by 10.42%, and ascorbic acid concentration by 16.75%. The interaction between the N and P levels of 140:42 mg L^-1 and the arbuscular mycorrhizal fungus (AMF) species <i>Glomus mosseae</i> resulted in the highest improvement in growth, yield, and fruit quality-related traits. Among the cultivars, Rio Grande exhibited the greatest root colonization, plant dry matter content, N, P, K uptake, plant height, Chl a, Chl b, and yield when compared to the control. In contrast, cultivar Nadir showed the highest stem diameter, fruit size, firmness, ascorbic acid, fruit juice contents, and TA. This study recommends that AMF inoculation in combination with a low N and P supply can be promising for improving tomato growth, productivity, and fruit quality on a commercial scale with minimum threats to the environment and human health. This study suggests the exploration of long-term sustainability and scalability of AMF inoculation methods in diverse agricultural settings.