Soil mapping provides detailed information on soil variability across a field, helping optimize crop nutrition, improve yields, and ensure long-term soil health. To achieve accurate soil mapping, it is essential to measure the basic properties of the soil using the appropriate sensors. Electrical conductivity (EC) is a fundamental property of materials that characterizes their ability to conduct or resist electricity. In agriculture, soil EC is the most widely used parameter for management zone delineation because it shows high temporal stability, as it is related to several soil physical and chemical properties. EC data can be translated into valuable agronomic insights with relatively high accuracy. increasing in soils with higher salt concentration. At the same time, salt concentration depends on water content and, therefore, on soil moisture. Once an EC sensor has scanned the entire field, georeferenced data is collected in the form of points to create a map that demonstrates the spatial variability of the measured parameter. Measured soil properties can provide insights into crop vigor, which can be used to adjust fertilization inputs.

Potato cultivation requires specific management in agricultural inputs in order to achieve proper growth development and yield. Excess use of Nitrogen inputs can lead to excessive vegetative growth that causes delay in tuber formation, and increases sensitivity to diseases such as Phytophthora rot, while low phosphorus input can lead to poor root and tuber development, reducing yield. In order to address these issues, vegetation indices can be created by acquiring data from proximal and remote sensing sensors. Drones mounted with multispectral camera can provide images from different zones of the spectrum (green, red, red-edge, near infrared) which can be merged to generate vegetation indices, like NDVI and proximal sensors (Trimble Greenseeker) which can directly provide NDVI values directly at a specific area of the potato crop. Furthermore, thermal cameras can be used to identify water stress of the potato crop to optimize irrigation. By receiving information about the health of the potato crop from vegetation indices, management of potato nutrition can be optimized to accomplish proper growth development and yield.

It is essential for maize cultivation to be monitored in order to assess the efficiency of the fertilization and irrigation plan. Nutrient deficiencies induced by improper fertilization can lead to stunted growth, poor grain and root development, and leaf edge necrosis. Nitrogen over-fertilization may cause leaf tip burn and excessive vegetative growth with poor grain filling, while maize crop water stress at critical stages can significantly impact yield and quality. Satellite imagery may be used to monitor maize crops, offering high resolution data for crop monitoring while storing data from previous years of cultivation for comparison. Applications such as SNAP (a free application by ESA) provides continuous satellite data which can be processed using Geographic Information Systems (GIS). These tools enable the creation of vegetation index maps and thermal maps, allowing for the precise identification of fertilization and irrigation issues within specific areas of the maize field. Farmers can thus make real-time decisions that optimize fertilization and reduce input waste according to the needs of the cultivation.

The potato crop is one of the most high-cost productions which has high risks of soil, water and nitrate pollution from fertilizers applied. Βy using Crop Sensing Technologies (CSTs), innovative technologies are adapted to cropping systems, focusing on smart farming services in potato crops. Specifically, system data are collected from sensors installed in the field recording atmospheric, soil and plant parameters (e.g., temperature, humidity, precipitation, atmospheric pressure, wind speed, soil moisture, leaf temperature). All the aforementioned data are collected to a central cloud computing repository, processed, combined and converted into fact-based advice for the optimisation of procedures for irrigation, pest management and fertilization. The advice is then communicated to the farmers through web-based applications. Farmers lag behind in terms of the adoption of smart technologies that optimise the use of external inputs and the implementation of regulated deficit strategies, while few attempts have been made by researchers and document benefits to the farmers considering environmental, social and economic factors.

Management of fertilizer application is essential for wheat production and environmental safety. The objective of the practice is to reduce fertilizer losses and optimize efficiency of fertigated wheat crops. The use of drone imaging for fertilization is a procedure which is used to locate where the field needs more or less fertilizer application to optimize the use of the fertilizer and avoid leaching and run-off. The procedure starts by taking images of the field from a drone which can be analysed in a computer by using GIS programs, such as ArcGIS, where  vegetation index maps indicate essential information can be created, aiming to detect which plants have higher or lower needs of fertilization. Subsequently, for the information received, a spraying drone can apply the correct doses of fertilizer in every spot in the field. The technical part of the procedure can also be implemented by a company with experience in this sector. Finally, the benefits of this practice are the mitigation of the leaching and run-off of the fertilizer which results in providing environmental protection and saving fertilizer costs, as well as an increase in the yield of the wheat.

In Greece, improper use of nitrogen fertilizers can result in water pollution. Nitrogen is an essential nutrient for wheat, ensuring both high yields (due to an increase in the number of ears per unit area), the number of grains per ear, and the specific weight of grains. An effective solution involves assessing available nitrogen levels in the soil to ensure precise fertilizer application for wheat crops. The Kjeldahl Method is pivotal in this determination by extracting and quantifying the "plant available" nitrogen in soil samples.

This method involves three phases: converting nitrogen into nitric acid through organic material digestion, distilling released ammonia onto an absorbing medium, and volumetrically analyzing the resulting ammonia. The measured nitrogen content allows for the creation of a soil map that can be integrated into smart tractor systems equipped with specialized software. This integration enables accurate fertilizer dosing for wheat crops based on the soil's nitrogen levels. This practice mitigates environmental impacts from excessive soil use and enhances resource efficiency, including optimized fertilizer and water use.

Soil structure helps to increase water and nutrient retention for sustainable cropping system.
The spade test is a cheap and reliable on-field method to assess the soil resistance  using a rod driven vertically into the ground and identify potential areas of compaction.
A steel tube with a conical tip is driven into the ground recording the soil resistance. The higher the resistance of the soil and the more difficult it is to push the rods in, the better the soil quality, the more stable it is or the higher the bearing capacity. Based on the results of the penetrometer test and taking into account the geological data available for the soil studied, it is possible to deduce the composition of the soil.
It is necessary to measure the soil moisture profile in order to interpret the curves, as this test is very sensitive to soil moisture.
This is an indirect measure of soil structure that can complement other indicators such as the spade test.
It can be used to identify a structural problem, to assess the depth of compaction, and to reason intervention according to the problem identified and the following crop. Other factors can influence resistance, in particular soil moisture.

Measuring soil mineral nitrogen stock (nitrogen residue) in post-winter period is crucial for adjusting and optimizing crop fertilization plans effectively. Nitrogen residue levels vary annually, influenced by previous crop nitrogen absorption efficiency, presence of intercrop cover, and winter leaching intensity.  Sampling should occur within the largest homogeneous area of the plot, with at least 14 core samples forming a representative sample, within a 20-meter diameter circle for accurate results. Ideally, samples should cover the full rooting depth of the considered crop, in 30 cm increments. Samples from each depth horizon should be mixed to create a composite sample. Samples should be collected post-winter, after winter rains and before humus mineralization resumes, to estimate nitrogen residue. Samples should be refrigerated (4°C) and delivered to the lab within 2-3 days or frozen (-18°C) for delayed delivery, identified and accompanied by a sampling sheet for analysis guidance.

The Spade Test, an ISARA Method, addresses the critical need to assess soil structure directly in the field for resilient soil and sustainable cropping. This method offers a cost-effective solution to observe the upper layer's structure (0-25 cm) and diagnose soil tillage issues, aiding decisions on whether to till the soil, especially in cases of heavy compaction. The test distinguishes clods into types Γ (gamma), Δ (delta), and Δb, providing insights into their internal structure, porosity, and biological activity. Additionally, it evaluates the mode of clod aggregation, indicating the state of soil macroporosity crucial for water infiltration and root penetration. With practical applications and detailed classifications, the Spade Test facilitates effective soil management and crop health assessment, contributing to sustainable agricultural practices.

Soil structural stability is vital for resilience and erosion prevention, with the Slake Test Method offering a cost-effective solution. This method assesses soil aggregates' resistance to erosion through rapid wetting, involving steps like drying aggregates, immersing them in water, and grading their stability. Scores range from 0 to 6, with lower scores indicating reduced stability and higher scores (>5) indicating good resistance. It's applicable to both surface and sub-surface layers, though sandy soils may not achieve the maximum score. Factors like soil texture, organic matter, and compaction influence stability, cautioning against comparisons between different plots. Monitoring stability changes over time within the same plot is advised. Additional resources for conducting the test and assessing soil quality are provided, including a French video demonstration and a guide from the NRCS.