Overview
Laser technology is revolutionizing agriculture, providing innovative solutions to long-standing challenges and transforming global farming practices to improve efficiency and sustainability.
Laser technology was originally used in the medical field. With the development of photobiology and photochemistry, the application of laser technology has been extended to the agricultural field. The economics and effectiveness of laser technology make it a common tool for precision agriculture, complementing other technologies such as drones and Internet of Things (IoT) sensors. This integration makes crop cultivation more efficient.
Lasers: Applications and Advantages in Agriculture
1. Soil element analysis
Soil is a complex mixture of organic matter, minerals, air and water, which is essential for plant growth and global climate regulation. However, human activities can pollute the soil with heavy metals, and plants can absorb these heavy metals and transfer these pollutants through the food chain, endangering the ecosystem and human health. Therefore, monitoring soil composition is essential to protect the environment, agriculture and public health.
Laser-induced breakdown spectroscopy (LIBS) has become a powerful tool in this field for rapid and accurate elemental analysis of soil components. Laser-induced breakdown spectroscopy (libs) focuses high-energy laser pulses on the soil surface to produce microscopic plasma, which emits characteristic spectra for accurate elemental analysis. The wavelength of the spectrum indicates the type of element present, while the intensity reflects its concentration.
This technology enables rapid, in situ detection of nutrients, heavy metals, and pollutants, helping to develop targeted soil management strategies that minimize environmental impacts.
A study published in Science of the Total Environment used LIBS to analyze macro nutrients (magnesium, calcium, potassium, phosphorus) and micronutrients (iron, copper, sodium, zinc, manganese) in soil fertilizers. The researchers compared single-pulse and double-pulse configurations and found that DPLIBS greatly improved the detection limit, making it a promising technique for qualitative analysis of soil fertilizers without chemical sample preparation.
Companies such as Applied Spectra and SciAps offer LIBS-based analyzers for agricultural applications that provide real-time insight into plant health and nutritional status.
2. Laser biological stimulation
Laser biostimulation is a promising and sustainable method to improve seed germination, plant growth, and stress resistance.
When a seed or plant is exposed to a specific wavelength of laser light, such as He-Ne at 632.8 nm, Nd: YAG at 532 nm, or LEDs in the visible spectrum, the photons are absorbed by light-absorbing molecules (chromophores) in the plant cells. The absorbed energy triggers a series of photochemical reactions and signaling pathways that increase germination, improve growth parameters (including root length, shoot length, and seedling quality), and improve yield characteristics.
Laser biostimulation also enhances plant biochemical properties, such as increasing the concentration of proteins, antioxidants, and enzymes involved in stress defense mechanisms. These changes improve the tolerance of plants to drought, salinity, ultraviolet radiation and disease.
3. Application of laser in land leveling
Laser leveling systems enable high-precision land leveling of ± 1 cm, which is essential for efficient crop management and irrigation practices.
The system comprises a laser transmitter and a receiver for transmitting and detecting laser light, and the received signal contains elevation data. This data drives the hydraulic system and the scraper blade to precisely grade the ground.
4. Weed control
Traditional weed control methods such as herbicides and tillage have raised environmental concerns and prompted the search for sustainable alternatives. Laser technology offers a promising solution to precisely locate and remove weeds through thermal or mechanical methods.
Laser weeding system can precisely irradiate the target weeds with high-energy laser beams, which can cause local heating of weeds, and then cause dehydration or tissue damage.
This highly selective method targets only identified weed species without harming surrounding crops. It also eliminates the need to apply broad-spectrum herbicides, reducing environmental impact and the potential for herbicide resistance.
A study published in Arogonomy investigated the effects of laser treatment on the apical meristem at the cotyledon stage of certain weed species (Brassica napus, Tripleurospermum inodorum, and Stellaria media). The researchers studied different lasers, spot sizes, and energy doses on potted weeds and observed that the growth of the weeds was significantly reduced and, in a few cases, the weeds died.
Emerging Trends and Innovations
1. Combine with advanced technology
Laser sensors on UAVs or robots enable high-resolution, wide-field mapping, providing real-time data on terrain elevation, soil moisture, and crop health. These data can be analyzed by artificial intelligence algorithms to make informed decisions and integrated with Internet of Things (IoT) devices to achieve precise operations in agriculture.
Recently, Carbon Robotics' LaserWeeder robot was named the "Best Agricultural Solution Based on Artificial Intelligence" in the AI Breakthrough Awards. The AI-powered robot, which kills up to 99% of weeds, can operate on two acres of land per hour and destroy up to 5,000 weeds per minute. It does not damage crops, and farmers using it can reduce weed control costs by up to 80%.
2. Sustainability and environmental impact
Agriculture is a major source of global greenhouse gas (GHG) emissions, accounting for nearly 13.5% of total anthropogenic emissions. Precision agriculture practices using laser systems provide a way to reduce chemical use, minimize environmental footprints, and support sustainable agricultural practices worldwide.
A study in Agronomy compared the effects of Precision Land Leveling (PLL) and Conventional Land Leveling (TLL) in sugarcane fields over six years (2009 to 2015), demonstrating the benefits of PLL. The results show that precision land leveling has higher energy productivity (90.7 – 198.6 GJ ha − 1), land use efficiency (64.9 – 86.2%), and lower GHG emissions (5249.33 – 944.19 kg CO2 EQ ha − 1 yr − 1) than conventional land leveling.
Laser Technology for Agriculture: Challenges and Innovative Solutions
Despite the promising advantages of laser technology, there are still significant challenges to its widespread adoption in agriculture.
On the technical side, the reliability of laser sources and sensors and the need for regular recalibration pose significant obstacles, as their performance degrades over time.
From a socio-economic point of view, the acceptance of laser technology by the agricultural community, especially in tropical areas, may be sceptical in terms of its technical and economic benefits. However, there are significant benefits to incorporating laser technology into agriculture, including precision land farming, improved crop yields, and resource efficiency.
Continued research into the design of new laser materials and systems can drive technological progress and improve efficiency and cost-effectiveness.
Continued research into new laser materials and system designs can drive technological advances, improve efficiency and cost-effectiveness. With supportive government policies, increased awareness and industry innovation, the adoption of laser technology can be accelerated, opening up new horizons for productivity and sustainability in the agricultural sector.
