Optical technology offers farmers new ways to boost output
Optimized optical emitters and sensors help growers to manage resource use better and raise yields.
How optical technologies impact modern farming
Optical technology offers farmers new ways to boost output
The farming industry is being squeezed from multiple directions at the same time. Hampered by the scarcity of key resources – like fresh water, and people to cultivate and harvest crops and to tend livestock – farmers are also facing the demand to increase production to meet the food needs of a global population which is predicted to rise from 8.2 billion today to 9 billion in 2037. The world’s population is expected to peak at 10.3 billion in the mid-2080s, according to a United Nations forecast.
Climate change and population pressure have given rise to previous ‘green revolutions’, which have increased yields through the improved use of fertilizers, more intensive mechanization, and genetic breakthroughs, breeding seed varieties which produce more tonnage per hectare while being more resilient against drought, disease or other stress factors. The big gains via these methods have been made, however, and these technological fixes now offer diminishing returns. It is time for agriculture to adopt new smart technologies in the farm of the future.
These smart technologies include lighting for indoor farms, light sensors for non-destructive testing of produce, and optical navigation systems for agriculture robots. ams OSRAM is ready to put its optical semiconductor technology at the service of this industry on which every person on the planet depends.
Easing water stress with optimally lit indoor farms
According to a 2024 paper in the Journal of Water Process Engineering, ‘severe scarcity of water is faced by around 4 billion people’. Factors such as global warming and urbanization are important causes of water shortages, but the paper says that 80 to 90 percent of all fresh water is consumed by agriculture, while its water use efficiency is on average just 45 percent.
The need to conserve water has given impetus to the growing number of indoor farms and greenhouses. This is due to the fact that these installations can implement a closed-loop water process, collecting the vapor released by crops and recycling it for use in irrigation.
Indoor farms serving local urban communities and growing perishable crops such as salad leaves, tomatoes, and strawberries help to reduce the climate impact of agriculture by dramatically cutting food miles, as cultivation takes place close to consumers and points of sale.
Indoor farming is becoming more and more economically attractive thanks to improvements in the application of highly efficient LEDs – sometimes LEDs with a white light output, but increasingly combinations of blue and hyper-red emitters which provide the most efficient growing light.
LEDs from ams OSRAM are highly valued for their quality as well as their wall plug efficiency, which is a measure of how much electrical energy is directly converted into light. Quality in horticultural LEDs strongly affects productivity: a luminaire that allows for tightly controlled emission of a plant-specific wavelength mix, intensity and beam pattern enables growers to reliably optimize illumination for each plant species, helping them to produce the highest yields with the lowest possible energy input. In addition, research has shown that active, spectrally optimized illumination allows for a substantial reduction in the amount of pesticides applied to crops.
In greenhouses, LED lighting is also being combined with light sensors which measure how much sunlight is reaching a crop, and even analyze the spectral characteristics of the ambient light. With this data, growers can determine when to supplement natural sunlight with LED lighting to provide the optimal intensity and color of illumination to the plants, while saving energy and cost by turning off or reducing the intensity of the artificial lighting whenever sufficient ambient light is available.
Depending on the distance, dTof or proximity sensors can play their part here too, by measuring the distance between a plant and a luminaire: as the plant grows towards the lamp, the power fed to the LEDs can be reduced. This takes account of the higher leaves’ tendency to shade the lower part of a plant. Without this ability to adapt the output in response to the proximity of a plant, the luminaire produces more light than the plant can use for photosynthesis, resulting in the waste of electrical energy.
Minimizing food waste with non-destructive inspection
According to the UN Environment Programme (UNEP), 1.05 billion tonnes of food waste were generated globally in 2022, amounting to 132kg per person. The UNEP says that out of the total food wasted in 2022, 60 percent happened at the household level, with food services responsible for 28 % and retail for 12 %.
Waste also occurs further upstream, when crops are in transit from the farm, and even at the farm itself. This is due in part to the difficulty for growers of shipping products through complex supply chains. With sometimes weeks between harvesting and the product appearing on the supermarket shelf, growers have to perform long-range forecasting of the time it will take their crop to ripen. Picked too late, the crop could have perished before it reaches the customer, adding to the mountain of food waste. Picked too early, the crop will not have reached full size, limiting the yield and threatening the grower’s profit.
Near infrared (NIR) spectrometry provides a way to monitor the condition of crops all the way from farm to fork, helping to reduce the waste which occurs when food products perish before consumption. NIR spectrometry is an established branch of science for materials analysis. It can be used to measure the sugar and water content of crops such as fruit: these measurements provide a gauge of the fruit’s ripeness.
The spectrometer operates non-destructively, by measuring reflections from an NIR light source directed at the crop in question. Traditionally NIR spectrometry has required huge, expensive laboratory equipment, unsuitable for use on the farm, in the warehouse, or in the supermarket.
Now however, chip-scale spectral sensors offering sensitivity in the visible and NIR spectrums can be integrated into low-cost, portable spectrometers for use by growers, food processors and retailers. There are numerous applications for spectral sensors such as the AS7343, from harvesting to sorting to merchandizing.
New research describes the scope for spectral and optical sensing in indoor farming as well, for example to analyze plant tissues, evaluate crop quality and yield, measure nutrients, and assess plant responses to stress.
Advanced automation eases burden on stretched workforce
Drones are commonly used for top view vision solutions on ground structures or to inspect inaccessible areas like wind turbines, while robots support tasks in manufacturing and logistics. But in fact both technologies can help to provide a solution for the looming shortage of agricultural workers.
Particularly in the highly industrialized parts of the world, the population is aging, and the ratio of retired people to active workers is rising. So competition for people of working-age is becoming more acute across all sectors of the economy. This trend is certainly being felt in agriculture: European Union research shows that 57.6% of farm managers in Europe were older than 54 years of age, while only 11.9% were under the age of 40. European agriculture faces a workforce crisis as today’s cohort of farmers enters retirement.
Automation can do much to mitigate the effect of the scarcity of farm workers. Robots today are in use for cultivation functions such as weeding and sowing. Mounted on a robot, powerful light sources such as blue lasers can be used to kill weeds, and ultraviolet LEDs to prepare soil for sowing, reducing the use of pesticides. Artificial intelligence (AI) will increasingly enable robots to distinguish plant types by analyzing pictures of leaves captured by robust image sensors.
To release farm workers from tasks such as weeding, sowing and ploughing, robots and tractors will need to navigate autonomously: here, an array of ranging and detection sensors enable the device to ‘see’ its environment, detect and avoid objects, and perform simultaneous location and mapping functions.
Automation can also take flight with drones, allowing the farmer to map and monitor their fields from their farm office desk. Optical sensor technology comes into play here too: for example, short-wavelength infrared (SWIR) sensor technology can measure the moisture in soil from high up in the air, and cameras allow for remote monitoring of the condition of crops in the fields.
Better for society, better for the grower
The application of advanced optical semiconductors promises to enable a new generation of tech-savvy farmers to increase productivity and automate operations, while reducing their use of inputs such as water, pesticide and fertilizer. By embracing the potential of innovative optical technology, farming can continue to feed a growing global population, even in the face of the challenges of climate change and aging populations.