Near-infrared Reflective Diffusion Coating Is Beneficial for Asparagus Summer Production in a Simple Plastic Greenhouse

Asparagus is a potential greenhouse crop, and its production is considerably affected by temperature and light, especially in the summer season. This study investigated the effects of the application of near-infrared (NIR)-reflective diffusion coating on a simple plastic greenhouse on microclimatic conditions, plant response, spear yield, and quality of the asparagus plant in central Taiwan. The results showed that NIR-reflective diffusion coating reduced the mean air temperature inside the greenhouse by 0.3 to 0.9 °C and leaf temperature by 2.3, 2.4, and 2.4 °C at a canopy height of 50, 100, and 50 cm, respectively. Although the accumulated daily light integral (DLI) transmitted in the coated greenhouse exhibited an 18.9% reduction compared with a 16.8% reduction in the noncoated greenhouse, a more uniform spatial light distribution was noted. Therefore, photosynthesis improved in the middle and bottom canopy, and plants could maintain a higher transpiration rate, thus resulting in atmospheric cooling. The average spear yield increased by 31.4% in summer and by 10.1% during the following harvest with a lower crude fiber (CF) content and higher Ca as well as Mg contents. In addition, the number of newly emerged shoots increased by 48.8% after the removal of the mother stalk under coating. NIR-reflective diffusion coating can be used as an energy-saving method for enhancing cooling and improving light use efficiency, thus increasing asparagus production in a greenhouse in summer.

Studies of microclimatic conditions in summer moong as influenced by different mulches

A field experiment was conducted during summer season of 1990 at research farm of Department of Agricultural Meteorology, Haryana Agricultural University, Hisar to study the microclimatic conditions in moong with the use of mulches. Latent heat enelgY and sensible heat energy were the main components of net energy. Among the various treatments, the latent heat energy use was found higher in black polythene sheet mulch. Soil temperature values were low in straw and white polythene mulch than black polythene mulch treatment

Reuse of Pruning Waste from Subtropical Fruit Trees and Urban Gardens as a Source of Nutrients: Changes in the Physical, Chemical, and Biological Properties of the Soil

A field experiment was conducted on the Andalusian coast (Granada, Southern Spain) to study the time course of nutrient release into the soil after the addition of bagged pruning waste from subtropical orchard trees (avocado, cherimoya, and mango) and urban garden waste over three two-year periods. N, P, and K concentrations were greater in the garden waste, whilst avocado and cherimoya pruning waste registered the highest values for Mg. In general, micronutrient contents were low in all waste, especially Cu. Macronutrient release followed a three-phase dynamic: fast initial release, intermediate stabilization, and final increase. Garden waste showed a similar time course in all three trees and released greater concentrations of K and P. The annual decomposition rate factor k was negative for N and Ca in the avocado tree, indicating strong biological activity in this plot. Avocado, cherimoya, and garden waste showed a good microbial degradation, improving soil quality by increasing carbon and nitrogen contents as well as soil microbial activity. As for the mango tree, its special microclimatic conditions appeared to favor waste photodegradation, thus eliminating nutrients that were not incorporated into the soil. Soil enzymatic activities increased in the avocado and cherimoya trees with the addition of all waste. In the mango tree, only an increase in urease was detected after the addition of garden waste. Our results suggest that the time course of organic waste in different subtropical trees grown on similar soils is significantly conditioned by the microclimatic characteristics.

Software Architecture of an Automated Greenhouse Complex based on Cloud Technologies

To grow crops in greenhouse complexes, it is necessary to maintain the microclimatic conditions required for these crops and monitor them. Automation of these processes is an urgent task, and for its solution it is necessary to use both hardware and software. The paper proposes a cloud service architecture for managing robotic vertical farms, which allows for reliable two-way data transfer between the greenhouse modules and the operator and can be used for growing crops both in vertical hydroponic installations and in single-level greenhouses of greenhouses. The business processes are described that allow you to understand and evaluate the principles of organizing monitoring and management of cultivation. On the basis of the developed architecture, software has been implemented, which has been tested in the tasks of managing the greenhouse complex and obtaining data on the microclimate. Thanks to the use of wireless networks, the absence of restrictions on the type and location of modules, duplication of functionality and data replication, such a system can be considered flexible in use and scalable.

Study of microclimatic conditions under different environments in wheat crop

An experiment was cunducted to study the wheal microclimate for higher grain yield production at research farm of Hisar 'Agriculture’ University (HAU). Profiles of temperature relative humidity, leaf temperature leaf wetness wind speed were measured in the crop canopies of different sowing treatments. Higher air temperatures and lower soil moisture were observed during reproductive phase under delayed sowings. Albedo varied between 0.19 and 0.23. Test weight decreased with delay in sowing time. Sowing of wheat between 31 October and 14 November produced statistically higher yield under favourable microclimate conditions at dirrerent phenophases.

Effect of Sampietrini Pavers on Urban Heat Islands

Cool pavements are reflective and/or permeable pavements that improve microclimate of urban areas where heat islands cause discomfort to citizens. Stone pavements lower surface temperatures and reduce the amount of heat absorbed. This study assessed, using ENVI-met 4.3 LITE software, how air temperature and predicted mean vote depend on physical properties of the road pavement. A comparative microclimatic analysis was implemented on a rectangular square in Rome (Italy) in the summer, paved in three different ways: asphalt, traditional sampietrini, and permeable sampietrini. The model considered local weather parameters, surrounding fabric, and vegetation to give reliable results in terms of numerical and graphical output using the application tool Leonardo. The tested pavement types affected air temperature during the day, but did not influence this variable in the early morning. Permeable sampietrini pavement was more effective than traditional sampietrini pavement in reducing air temperature compared to the current asphalt surface. The road pavement did not, however, affect human comfort in terms of predicted mean vote. The obtained results are useful for further investigation of parameters that could modify the microclimatic conditions of urban areas.

Energy and Water Related Parameters in Tomato and Cucumber Greenhouse Crops in Semiarid Mediterranean Regions. A Review, Part II: Irrigation and Fertigation

Increasing agricultural systems’ resource efficiency is the key action for producing adequate food quantities in semi-arid Mediterranean regions while coping with water scarcity, environmental constraints and economic issues. Optimisation of irrigation and fertigation practices imposes different approaches, considering plant-water-soil relationships based on prevailing greenhouse microclimatic conditions, ensuring optimal production per drop of water and unit of fertiliser. In the content of "precision agricultural farming systems", nutrient uptake modelling, phyto-sensing, smart and sustainable technologies must be applied for monitoring and evaluating water and nutrients crops supply. However, in many cases, the use of irrigation and fertigation recipes given in the literature may not be compatible in the Mediterranean, as they usually originated based on northern European climatic conditions. The objective of this work is an attempt to understand various aspects of irrigation and fertigation management in vegetable fruiting crops such as tomato and cucumber towards nutrients and water resource sustainability in Mediterranean greenhouses.

Computation of vapour pressure deficit and crop transpiration via development of a web based computer module

The plant water or nutrient requirement under greenhouse conditions is mainly governed by crop transpiration in a linear relation to vapour pressure deficit (VPD), particularly in soilless production systems. Being a cooling process in plants, transpiration governs the plant water requirement in relation to the subjected microclimatic conditions and VPD can be used as a tool to maintain greenhouse crop transpiration to optimal range for obtaining desired crop yields. Thus, the present investigation was undertaken to study the integrated effect of temperature (Tapc), relative humidity (Eapc) and solar radiation (Irad) on VPD and crop transpiration. A computer module was developed to monitor the behavior of the VPD and thereby the crop transpiration through charts under greenhouse conditions. The VPD indicated a linear increasing trend with Tapc (R2≥0.84) and decreasing trend with Eapc (R2=0.99), demonstrating a strong correlation in both cases. The increasing crop transpiration with VPD, particularly under hot climatic conditions significantly increased the input water and nutrient requirements of the crop. Thus, transpiration in relation to VPD should be considered as a factor for fertigation scheduling and improving irrigation control in soilless systems. Moreover, maintaining Tapc, Eapc and VPD within range of 22-27°C, 60-80% and 0.53-1.10 kPa may help to control the crop transpiration, manage the greenhouse irrigation and fertigation, and thus improve the cucumber yield.