  Citation: Hilal, Y.Y.; Khessro, M.K.; van Dam, J.; Mahdi, K. Automatic Water Control System and Environment Sensors in a Greenhouse. Water 2022, 14, 1166. https://doi.org/10.3390/w14071166 Academic Editor: José Alberto Herrera-Melián Received: 1 March 2022 Accepted: 21 March 2022 Published: 6 April 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). water Article Automatic Water Control System and Environment Sensors in a Greenhouse Yousif Yakoub Hilal 1, * , Montaser Khairie Khessro 1 , Jos van Dam 2 and Karrar Mahdi 2 1 Department of Agricultural Machines and Equipment, College of Agriculture and Forestry, University of Mosul, Mosul 41002, Iraq; montaser.hussain@uomosul.edu.iq 2 Soil Physics and Land Management Group, Wageningen University & Research, 6708 PB Wageningen, The Netherlands; jos.vandam@wur.nl (J.v.D.); karrar.mahdi@wur.nl (K.M.) * Correspondence: yousif.yakoub@uomosul.edu.iq; Tel.: +964-77-3101-6244 Abstract: Iraqi greenhouses require an active microcontroller system to ensure a suitable microclimate for crop production. At the same time, reliable and timely Water Consumption Rate (WCR) forecasts provide an essential means to reduce the amount of water loss and maintain the environmental conditions inside the greenhouses. The Arduino micro-controller system is tested to determine its effectiveness in controlling the WCR, Temperature (T), Relative Humidity (RH), and Irrigation Time (IT) levels and improving plant growth rates. The Arduino micro-controller system measurements are compared with the traditional methods to determine the quality of the work of the new control system. The development of mathematical models relies on T, RH, and IT indicators. Based on the results, the new system proves to reliably identify the amount of WCR, IT, T, and RH necessary for plant growth. A t-test for the values from the Arduino microcontroller system and traditional devices for both conditions show no significant difference. This means that there is solid evidence that the WCR, IT, T, and RH levels for these two groups are no different. In addition, the linear, two-factor interaction (2FI), and quadratic models display acceptable performance very well since multiple coefficients of determination (R 2 ) reached 0.962, 0.969, and 0.977% with IT, T, and RH as the predictor variables. This implies that 96.9% of the variability in the WCR is explained by the model. Therefore, it is possible to predict weekly WCR 14 weeks in advance with reasonable accuracy. Keywords: Arduino microcontroller; environment; sensors; models; greenhouses 1. Introduction Agriculture is a pillar of the economic lifeline, but traditional, broad forms of agri- culture are no longer able to meet the development requirements of modem agriculture; therefore, developing precision agriculture has become an inevitable trend. Water repre- sents a natural extension of the agricultural concept. Water is vital for farm production, and more water can increase crop production [1]. Irrigation allows farmers to apply nutrients more precisely and uniformly to the wetted root volume, where the active roots are con- centrated. When environments of plants are consistently maintained and kept within their comfort zone, plants are more photosynthetically efficient and can grow stress-free [2]. In arid and semi-arid zones, the main constraints limiting crop production in open fields are the scarcity and disparity in rainfall, high temperatures, extreme solar radiation, and the spread of weeds and diseases [3,4]. Since the beginning of this century, agriculture in Iraq has undergone many changes [5,6]. Agriculture was making valuable contributions to the Iraqi economy until production costs rose and farmers lacked any real support from the government. Neighbouring countries began to produce more at lower prices, and Iraqi farmers struggled to compete. Luckily, in the past few years, agriculture has become the one sector that has contributed the most to national food security, economic growth, and employment [7–9]. Greenhouses can provide high-quality products year-round with effi- cient production resources, including fertilizer, water, pesticides, and labour. Countries like Water 2022, 14, 1166. https://doi.org/10.3390/w14071166 https://www.mdpi.com/journal/water