Greenhouse Requirements for Soilless Crop Production: Challenges and Prospects for Plant Factories

This chapter discussed the greenhouse requirement for soilless crop production. It further introduced soilless crop production and elucidated the equipment required for an efficient production system covering greenhouse environmental control and management of temperature, humidity, lighting, and nutrients using innovative strategies. Also, the energy required for the control of the greenhouse environmental conditions during the crop production cycle was explained. Identification and management of pests and diseases using wireless network sensors and the Internet of Things for efficient and safe food production were also highlighted. Finally, the challenges facing greenhouse crop production itemized, and the prospects of greenhouse technology for sustainable healthy food production were proposed

Modeling and optimization of environment in agricultural greenhouses for improving cleaner and sustainable crop production

Resource-use efficiency and crop yield are significant factors in the management of agricultural greenhouse. Appropriate modeling methods effectively improve the control performance and efficiency of the greenhouse system and are conducive to the design of water and energy-saving strategies. Meanwhile, the extreme environment could be forecasted in advance, which reduces pests and diseases as well as provides high-quality food. Accordingly, the interest of the scientific community in greenhouse modeling and optimizing has grown considerably. The objective of this work is to provide guidance and insight into the topic by reviewing 73 representative articles and to further support cleaner and sustainable crop production. Compared to the existing literature review, this work details the approaches to improve the greenhouse model in the aspects of parameter identification, structure and process optimization, and multi-model integration to better model complex greenhouse system. Furthermore, a statistical study has been carried out to summarize popular technology and future trends. It was found that dynamic and neural network techniques are most commonly used to establish the greenhouse model and the heuristic algorithm is popular to improve the accuracy and generalization ability of the model. Notably, deep learning, the combination of “knowledge” and “data”, and coupling between the greenhouse system elements have been considered as future valuable development

Greenhouse Management for Better Vegetable Quality, Higher Nutrient Use Efficiency and Healthier Soil

Greenhouse cultivation provides an artificially controlled environment for the year-round production of vegetables, and has played an increasingly important role in agriculture production systems in recent decades. Recent works have shown that improving greenhouse conditions can promote the growth of vegetables and enhance the uptake of nutrients, leading to better vegetable quality. Meanwhile, greenhouse conditions not only directly influence soil nutrient cycling processes and properties, but also indirectly affect them by regulating vegetable root growth and plant–soil interactions. This Special Issue features twelve original research articles that deal with the effects of novel greenhouse practices and strategies on the yield and quality of horticulture crops, as well as greenhouse soil properties. Among these publications, three studied the effects of fertilizers, including organic and macro- and micro-nutrient fertilizers, on the growth and nutrient uptake of vegetables. Two articles described the effects of water and nutrient supply using irrigation or hydroponic supplying systems on the yield and quality of vegetables. Four articles investigated the effects of environmental conditions (mainly light and temperature) on the growth and quality of vegetables. In terms of degenerated greenhouse soil, three articles showed how reductive soil disinfestation decreased soil salinity, improved soil quality, and inactivated soil-borne pathogens

Controlled release fertiliser as a management tool for productivity of tunnel-grown tomatoes

Thesis (MScAgric)--Stellenbosch University, 2022.ENGLISH ABSTRACT: To be able to grow crops such as tomatoes on a commercial scale under stringent controlled conditions in what is termed controlled environment agriculture (CEA), requires a great amount of expertise and technology. Therefore, the aim of this study was to see if the use of controlled release fertilizer as an alternative low expertise and low technology-based fertilization method could produce the same yields and marketability than the conventional fertigation fertilization methods used in greenhouse tomato production. The study assessed this by (1) determining if the ratio of perlite to coco coir in the growth medium had any effect on the yield response to an industry recommended controlled release fertilization recommendation, (2) trying to establish an appropriate mixing ratio of controlled release fertilizer (CRF) and liquid fertilizer (LF) to determine if a follow up fertilization application of the pre-plant applied CRF can obtain improved yields. From the results it was evident that by applying a mixture of 80% CRF (based on the fraction of the total % nitrogen applied) and 20% LF with additional monthly manual application of calcium sulphate or calcium nitrate to each planting bag, CRF could potentially replace a 100% LF fertilization programme in greenhouse tomato production. Some results here indicate that a spike in temperature at the beginning of the growing season may have contributed to the premature release of nutrients from the CRF prill, causing a spike in EC. This stunted the growth of the plants for the rest of the season, which could have been attributed to an initial toxic level of salts in the rootzone and a prolonged deficit of other essential nutrients. The growth media trial for the determination of the optimal perlite: coco coir ratio revealed that a mix consisting of 20% perlite to 80% coco coir, or 40% perlite and 60% coco coir were the best ratios that yielded the highest. Thus, for tomato production the effect of CRF would be greatly improved if applied in an environment where the temperature and growth media properties are favourable for the slow release of the nutrients. The evidence here did not support the utilisation of 100% CRF as a replacement of the currently employed LF for commercial greenhouse tomato production. In addition, it is imperative that additional calcium (Ca2+), Sulphate (SO42-) and Nitrate (NO3-) be supplemented to reap the full benefits of CRF due to the ongoing technological research into the ability to coat calcium-based fertilizer products as a CRF.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.Master

Evaluation and modelling of different greenhouse microclimates under South African agro-climatic conditions.

Master of Science in Agricultural Engineering. University of KwaZulu-Natal, Pietermaritzburg 2016.Abstract available in PDF file

Energy performance and climate control in mechanically ventilated greenhouses: A dynamic modelling-based assessment and investigation

Controlled environment agriculture in greenhouse is a promising solution for meeting the increasing food demand of world population. The accurate control of the indoor environmental conditions proper of greenhouses enhances high crop productivity but, contemporarily, it entails considerable energy consumption due to the adoption of mechanical systems. This work presents a new modelling approach for estimating the energy consumption for climate control of mechanically ventilated greenhouses. The novelty of the proposed energy model lies in its integrated approach in simulating the greenhouse dynamics, considering the dynamic thermal and hygric behaviour of the building and the dynamic response of the cultivated crops to the variation of the solar radiation. The presented model simulates the operation of the systems and the energy performance, considering also the variable angular speed fans that are a new promising energy-efficient technology for this productive sector. The main outputs of the model are the hourly thermal and electrical energy use for climate control and the main indoor environmental conditions. The presented modelling approach was validated against a dataset acquired in a case study of a new fully mechanically controlled greenhouse during a long-term monitoring campaign. The present work contributes to increase the knowledge about the dynamics and the energy consumption of greenhouses, and it can be a valuable decision support tool for industry, farmers, and researchers to properly address an energy efficiency optimisation in mechanically ventilated greenhouses to reach the overall objective of decreasing the rising energy consumption of the agricultural sector

Optimising Soilless Culture Systems and Alternative Growing Media to Current Used Materials

This book represents a Special Issue collection called: “Optimising Soilless Culture Systems and Alternative Growing Media to Current Used Materials”. Nine original papers, one review, and an Editorial from 41 authors from different countries were published in this Special Issue. New strategies and technologies, including new sustainable raw materials, should be continually developed to solve specific cultivation limitations, optimise existing systems, reduce related environmental impacts, and address the impacts of climate change

Nutrient and water use of tomato (Solanum Lycopersicum) in soilless production systems

Thesis (PhD)--Stellenbosch University, 2015.ENGLISH ABSTRACT: Soilless production of crops relies on the addition of high concentrations of nutrients with the irrigation water. The drained nutrient solution should be re-used to reduce the risk of pollution and to increase the water- and nutrient use efficiency of the system. Besides the risk of pathogen build-up, one of the main impediments of a wider application of this method is the frequent analysis required to maintain optimum nutrient concentrations and ratios in the rootzone. Yield reductions may be caused by an unbalanced nutrient solution. Alternatively the addition level of nutrients can be calculated through the use of nutrient uptake models that simulate the change in the re-circulated nutrient solution. To simulate crop water and nutrient demand necessary for model based regulation it was necessary to quantify the key factors affecting nutrient uptake by plants. The nutrient solution concentration and ratios between the macro-nutrients affected the uptake of water and nutrients. The total nutrient uptake per root dry weight increased and more specifically the nitrate (NO3 -), phosphate (H2PO4 -), potassium (K+) and sulphate (SO4 2-) uptake increased with an increase in nutrient solution electrical conductivity (EC) from 0.8 to 4.0 mS cm-1 while water uptake decreased. Except for Ca2+ uptake there was no correlation between nutrient and water uptake. Nutrient uptake can thus not be calculated based on water uptake. Instead a mechanistic high-affinity Michaelis-Menten based model can be used to estimate macro-nutrient uptake (Un, mg m-2 hr-1). Water and nutrient uptake was also affected by the solar radiation levels. Since nutrient uptake is related to the growth rate, solar radiation levels can be expected to influence nutrient uptake. The uptake of all ions increased with an increase in the solar radiation levels and for NO3 -, K+ and H2PO4 - the uptake rate was higher at higher nutrient solution concentrations. The Michaelis-Menten based model was adjusted to incorporate the effect of solar radiation levels on nutrient uptake. Water uptake (Wu, L m-2 day-1) was simulated as a function of crop transpiration and crop leaf area using a linear regression model, but since leaf area development was affected by solar radiation levels this was additionally incorporated into the estimation of the leaf area index (LAI). The composition of the nutrient solution also affected the biomass allocation of the crop which can again affect nutrient use as well as the fruit yield. There was also a direct effect of nutrient solution composition on fruit yield and quality with higher EC’s resulting in smaller fruit but an increase in fruit dry matter %, total soluble solids (TSS), titratable acidity (TA) and lycopene content. The results in this thesis make a valuable contribution to our understanding of the effect of nutrient availability (concentration and ratios) and nutrient requirement for growth (solar radiation levels) on nutrient uptake. Incorporating these into nutrient uptake models resulted in the development of a handy tool to simulate changes in composition of re-circulating nutrient solutions ultimately resulting in an improvement of the water and nutrient use efficiency of soilless systems.AFRIKAANSE OPSOMMING: Die grondlose verbouing van gewasse is afhanklik van toediening van voedingselemente teen hoë peile in die besproeiingswater. Die voedingsoplossing wat dreineer moet hergebruik word om die risiko van besoedeling te verminder en ook om die water en nutriënt verbruik doeltreffendheid van die sisteem te verbeter. ʼn Ongebalanseerde voedingsoplossing kan ʼn verlaging in opbrengste veroorsaak. Benewens die risiko van patogene wat opbou, is die gereelde analises nodig word vir die handhawing van optimale nutriënt konsentrasies en verhouding tussen elemente in die wortelsone een van die hoof faktore wat ʼn meer algemene gebruik van die metode verhoed. Alternatiewelik kan die nutriënt toedieningspeile bereken word deur voedingstof opname modelle en simulasie van die verandering in water en nutriente wat dreineer. Om ʼn model gebaseerde reguleringsmetode daar te stel was dit nodig om die belangrikste faktore wat nutriënt opname beïnvloed te kwantifiseer. Beide die konsentrasie van die voedingsoplossing en die verhouding tussen elemente het ‘n effek gehad op die opname van water en nutriënte. Die totale nutriënt opname per wortel droë massa het toegeneem. Terwyl water opname afgeneem het met ‘n toename in die elektriese geleding (EG) van die voedingsoplossing vanaf 0.8 tot 4.0 mS cm-1 het die nitraat (NO3 -), fosfaat (H2PO4 -), kalium (K+) en sulfaat (SO4 2-) opname verhoog. Behalwe vir Ca2+ opname was daar geen korrelasie tussen water en nutriënt opname nie. Nutriënt opname kan dus nie bepaal word gebaseer op wateropname nie. Alternatiewelik is die gebruik van ʼn meganistiese hoë-affiniteit Michaelis-Menten-gebaseerde model voorgestel om die opname van makro-nutriente (Un, mg m-2 hr-1) te bepaal. Water- en voedingstofopname is beinvloed deur die ligintensiteit vlakke. Voedingsopname word bepaal deur die groei van die plant, daarom is dit verwag dat ligintensiteit vlakke die opname van voedingstowwe sal beïnvloed. Die opname van al die ione het toegeneem met 'n toename in die ligintensiteit vlakke en die tempo van NO3 -, K+ en H2PO4 - opname was hoër by 'n hoër voedingsoplossing konsentrasie. Die Michaelis-Menten gebaseerde model is aangepas om die effek van ligintensiteit vlakke op nutriënt opname te inkorporeer. Opname van water (Wu, L m-2 dag-1) is gesimuleer as 'n funksie van transpirasie en blaaroppervlakte met behulp van 'n lineêre regressiemodel en aangesien die blaaroppervlak ontwikkeling ook deur ligintensiteit vlakke beïnvloed word, is dit opgeneem in die skatting van die blaaroppervlakte-indeks (LAI). Die samestelling van die voedingsoplossing het die biomassa verspreiding beïnvloed. Dit kan nutriënt gebruik en vrug opbrengs beïnvloed. Die voedingsoplossing samestelling het vrug opbrengs en - kwaliteit beinvloed met kleiner vrugte, maar 'n toename in droëmateriaal %, totale oplosbare vastestowwe (TOVS), titreerbare suur (TA) en likopeen inhoud by ʼn hoër EG. Die resultate in hierdie tesis lewer 'n waardevolle bydrae tot ons begrip van die effek van nutriënt beskikbaarheid (konsentrasie en verhoudings) en voedingstof behoefte vir groei (ligintensiteit vlakke) op voedingsopname. Deur die inligting te inkorporeer in voedingsopname modelle het gelei tot die ontwikkeling van 'n handige instrument om die veranderinge in die samestelling van hersirkulerende voedingsoplossings te simuleer. Dit lei gevolglik tot die verbetering van die water en voedingstof gebruik doeltreffendheid van grondlose stelsels