Agricultural productivity | EPFL Graph Search

Agricultural productivity is measured as the ratio of agricultural outputs to inputs. While individual products are usually measured by weight, which is known as crop yield, varying products make measuring overall agricultural output difficult. Therefore, agricultural productivity is usually measured as the market value of the final output. This productivity can be compared to many different types of inputs such as labour or land. Such comparisons are called partial measures of productivity. Agricultural productivity may also be measured by what is termed total factor productivity (TFP). This method of calculating agricultural productivity compares an index of agricultural inputs to an index of outputs. This measure of agricultural productivity was established to remedy the shortcomings of the partial measures of productivity; notably that it is often hard to identify the factors cause them to change. Changes in TFP are usually attributed to technological improvements. Agricultural productivity is an important component of food security. Increasing agricultural productivity through sustainable practices can be an important way to decrease the amount of land needed for farming and slow environmental degradation and climate change through processes like deforestation. Productivity is driven by changes in either agricultural technique or improvements in technology. Some sources of changes in agricultural productivity have included: Mechanization High yield varieties, which were the basis of the Green revolution Fertilizers: Primary plant nutrients: nitrogen, phosphorus and potassium and secondary nutrients such as sulfur, zinc, copper, manganese, calcium, magnesium and molybdenum on deficient soil Education in management and entrepreneurial techniques to decrease fixed and variable costs and optimise manpower Liming of acid soils to raise pH and to provide calcium and magnesium Irrigation Herbicides Genetic engineering Pesticides Increased plant density Animal feed made more digestible by processing Keeping animals indoors in cold weather See: Productivity improving technologies (historical) Section: 2.

Long-term effects of crop succession, soil tillage and climate on wheat yield and soil properties

Mathieu Raymond Santonja

Climate change is increasing crop losses and yield variability with impacts for global food security. In this context, conservation agriculture appears as a potential solution to maintain crop productivity, soil fertility and environmental sustainability. Therefore, understanding the combined effects of soil tillage and crop succession over a long period is of primary interest. In this study, we analyzed data from a 50 year long-term field experiment to assess (i) the change of climatic parameters, wheat yield and soil organic carbon (SOC) content; (ii) the combined effects of crop succession (monoculture vs. crop rotation) and soil tillage system (minimum tillage vs. plough) on wheat yield, SOC content and other soil properties at three soil depths (0-10, 10-20 and 20-50 cm); and (iii) the relative contributions of climatic parameters, wheat phenology and agricultural practices on wheat yield variability. Wheat yield was 16% higher in crop rotation compared to monoculture, while soil tillage system had no significant effect on wheat yield during the period 1977-2016. Despite a SOC content decline over time, which was especially marked during the first ten years of the study, SOC content was 7% higher in the minimum tillage treatment compared to the plough treatment, while crop rotation had no significant effect. In 2016, after 50 years of experimentation, both crop succession and soil tillage systems influenced soil properties. Over the 50-year period, the climatic conditions around the heading phase explained 22% of yield variability, while 18% of this variability was explained by crop succession and 6% by the growing degree days until heading stage. In a context of conservation agriculture promotion, our long-term field experiment provides key evidence that the combination of both minimum soil tillage and crop rotation improves soil fertility and crop productivity.

ELSEVIER SCIENCE BV2019

Cost and benefits of climate change in Switzerland

Philippe Thalmann, Marc Vielle, Frank Vöhringer, Boris Thurm, Dario Stocker, Wolfgang Knoke, Anita Frehner

Understanding the economic magnitude of climate change impacts is a prerequisite for developing adequate adaptation strategies. In Switzerland, despite new climate scenarios and impact studies, only few impacts have been monetized. Our objective is to assess costs and opportunities of climate change for Switzerland by 2060, while enhancing the assessment methods. Using inputs from bottom-up impact studies, we simulate the economic consequences of climate scenarios in a CGE framework. We cover health, buildings/infrastructure, energy, water, agriculture, tourism, the spill-overs to other sectors, and international effects. Due to data constraints, significant impacts have not been quantified, e.g. for heat waves and droughts more extreme than the 2060 average climate. For the considered impacts, welfare decreases by 0.37% to 1.37% in 2060 relative to a reference without climate change. Higher summer temperatures increase mortality and decrease productivity. Contrariwise, tourism benefits from extended summer seasons. Regarding energy, increased demand for cooling is overcompensated by savings in heating.

2019

Land-use change affects phosphorus fractions in highly weathered tropical soils

Thomas Guillaume

Deforestation and land-use change in tropics have increased over the past decades, driven by the demand for agricultural products. Although phosphorus (P) is one of the main limiting nutrients for agricultural productivity in the tropics, the effect of land-use change on P availability remains unclear. The objective was to assess the impacts of land-use change on soil inorganic and organic P fractions of different availability (Hedley sequential fractionation) and on P stocks in highly weathered tropical soils. We compared the P availability under extensive land-use (rubber agroforest) and intensive land-use with moderate fertilization (rubber monoculture plantations) or high fertilization (oil palm monoculture plantations) in Indonesia. The P stock was dominated by inorganic forms (60 to 85%) in all land-use types. Fertilizer application increased easily-available inorganic P (i.e., H2O-Pi, NaHCO3-Pi) in intensive rubber and oil palm plantations compared to rubber agroforest However, the easily-available organic P (NaHCO3-extractable Po) was reduced by half under oil palm and rubber. The decrease of moderately available and non-available P in monoculture plantation means that fertilization maintains only the short-term soil fertility that is not sustainable in the long run due to the depletion of P reserves. The mechanisms of this P reserve depletion are: 1) soil erosion (here assessed by C/P ratio), 2) mineralization of soil organic matter (SOM) and 3) P export with yield products. Easily-available P fractions (i.e., H2O-Pi, NaHCO3-Pi and Po) and total organic P were strongly positively correlated with carbon content, suggesting that SOM plays a key role in maintaining P availability. Ecologically based management is therefore necessary to mitigate SOM losses and thus increase the sustainability of agricultural production in P-limited, highly weathered tropical soils. (C) 2016 Elsevier B.V. All rights reserved.

Elsevier Science Bv2017