The main objective of this work was to evaluate technologies that have potential for monitoring aspects related to spatial and temporal variability of soil nutrients and pasture yield and for support to decision making by the farmers. Three types of sensors were evaluated: an electromagnetic induction sensor, an active optical sensor and a capacitance probe. The results are relevant for the selection of the adequate sensing system for each particular application and to open new perspectives for other works that would allow the testing, calibration and validation of the sensors in a wider range of pasture production conditions and rainfall patterns, characteristic of the Mediterranean region.

In order to exploit potentials of 20–40% reduction of herbicide use, as documented by use of Decision Support Systems (DSS), where requirements for manual field inspection constitute a major obstacle, large numbers of digital pictures of weed infestations have been collected and analysed manually by crop advisors. Results were transferred to: 1) DSS, which determined needs for control and connected, optimized options for control returned options for control and 2) convolutional, neural networks, which in this way were trained to enable automatic analysis of future pictures, which support both field- and site-specific integrated weed management.

Nitrogen is an essential nutrient in agriculture. Its reactive forms are the focus of concerns because they are responsible for a multitude of impacts on the environment and health. This was highlighted by the 2011 European Nitrogen Assessment, which drew up a critical inquiry on nitrogen imbalances due to livestock farming systems. The ambivalent status of nitrogen, both a resource for agriculture and a pollutant for environment, requires legal systems to find the equilibrium between the fertilising potential of the animal wastes and its possible negative effects on the environment. The European policies on nitrate and gaseous pollutants are the subject of much litigation with the European Commission. In this context, the French government asked for a synthesis of scientific knowledge on flows and fate of nitrogen related to livestock farms. Articles following in this review draw (i) the current situation, (ii) explain social and economic causes of the territorial variability of nitrogen pressure, (iii) quantify the flow on farms, (iv) look at indicators, (v) regulation instruments and finally (vi) identify options for reducing nitrogen pressure caused by livestock farming. In terms of materials and methods, a particular importance was given to peer recognition, and plurality inside the panel of experts and in the literature selection.

This article describes the nitrogen flows in the environment and points to the specificities of the livestock production. Till the beginning of the 20th century, the symbiotic fixation and the recycling of animal excreta supplied the nitrogen necessary for the fertility of soil. In 1913, the Haber-Bosch process allowed the industrial synthesis of ammonia and made possible the fertilisation without association of crop production with the livestock farming. The efficiency of the nitrogen in livestock farming is low with nearly half or more of the inputs losses to the environment. These losses have diverse impacts that intervene at various spatial scales owing to the nitrogen cascade. Quantitative assessment of nitrogen flows at the scale of regions started in the early 1980s in Western Europe and North America. These studies provided estimates of the spatial variability of nitrogen discharge within a region. They confirmed the differences between areas with a high animal density such as Brittany (western region, France) and other regions. It was also found that the same nitrogenous losses could lead to different levels of environmental impacts according to the sensibility of a given environment and its capacity to cope with nitrogen excess. Climate, soils characteristics, animal density, and proportions of agricultural land under annual and perennial crops are drivers of this sensibility.