Catálogo de publicaciones - revistas

<jats:title>Abstract</jats:title><jats:p>Cover crops (CCs) are a promising and sustainable agronomic practice to ameliorate soil health and crop performances. However, the complex of relationships between CCs, the soil, and the plant nutritional status has been little investigated. In this article, for the first time, we critically review, under a holistic approach, the reciprocal relationships between CCs and the soil physical and hydraulic properties, microbial, and faunal communities, soil nutrient availability, and plant nutritional status in temperate climates. For each of these topics, we report the current state of understanding, the influence of CC management options and suggested strategies, thus including both fundamental and applied aspects. In addition, we provide a detailed focus on the history of CCs and a list of the main temperate CCs. Cover cropping is a helpful practice in improving the physical, chemical, and biological soil properties, optimizing nutrient use efficiency and reducing the dependency of crops on external supplies of nutrients. The interactions between CCs and the nutritional status of soil and plants are complex and dynamic. Their understanding could be useful to set up an appropriate and site-specific management of fertilization. Management options play a key role in developing an effective and context-specific cover cropping.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Soil organic matter (SOM) is important in maintaining soil fertility and other ecosystem functions. Yet, land management in intensive agriculture has caused SOM level to decrease, with knock-on effects for soil fertility and quality. Therefore, land management options that ensure that SOM is not depleted and that soil functions are better sustained are of increasing interest. However, there is limited knowledge on how different land managements affect the composition of SOM and associated microbial functional profiles. Twelve long-term field experiments, covering a wide range of climatic zones and soil types, were selected in Sweden. They focused on the role of combining ley in crop rotations with the manure application (livestock farm), as opposed to the management without ley and receiving only inorganic fertilizer (arable farm). In ten out of the 12 study sites, livestock farm management tended to have higher proportions of aliphatic and double bonded C groups, as estimated by mid-infrared spectroscopy. This was further confirmed by <jats:sup>13</jats:sup>C NMR analysis, which found greater proportions of O-alkyl and di-O-alkyl groups and less aromatic C in livestock farm than arable farm management in five of the eight sites analyzed. The changes in SOM composition were reflected in microbial functional profiles across many sites: soils from livestock farm management utilized more carbohydrates and amino acids, while polymer and aromatic compounds were associated with arable farm management. Overall, shifts in both microbial functional profiles and SOM composition showed great consistency across geographical and climatic zones. Livestock farm management maintained higher levels of microbial functional diversity and were associated with higher proportions of “reactive” C functional groups. Our investigation demonstrates that livestock farm management could maintain soil fertility over the long-term via the changes in SOM composition and the regulation of microbial functional profiles.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Potato production in low-income countries is threatened by seed degeneration, i.e., the accumulation of seed-borne diseases and pests in potato seed tubers when these are vegetatively propagated over consecutive cycles, leading to a reduction in seed quality and yielding ability. Agroecological settings and seed recycling (on-farm propagation over consecutive cycles) determine the process of seed degeneration. However, it is poorly understood how these factors affect this process. Therefore, to reduce this knowledge gap, we analysed two datasets collected in Ecuador, one from a multi-annual field experiment and one from a farmers’ seed study. The experiment, carried out from 2013 to 2016, aimed to assess seed degeneration at agroecological settings present in three different altitudes. The farmers’ seed study, in which 260 farmers were surveyed in 2018, aimed to understand potato seed degeneration in farmers’ fields under diverse agroecological settings. Our results of the multi-annual field experiment showed that agroecological settings have a heterogeneous influence on the presence of seed-borne diseases and pests. We also found that both the agroecological settings at the three altitudes and the number of on-farm propagation cycles affected the rates at which seed-borne diseases and pests on the seeds increased and yield decreased. However, the farmers’ seed study challenged these results by indicating that this was not clear on farms. Combining these results, this article shows that agroecological settings and seed recycling only partially explain the process of seed degeneration. This suggests that more research about seed degeneration needs to also take place under farmers’ conditions to fully understand the complex of potato performance factors. We expect that such research will support the design of improved seed interventions, while simultaneously it may generate discussion about when potato seed degeneration plays an important role in productivity.</jats:p>

<jats:title>Abstract  </jats:title><jats:p>In the face of climate change, cropping systems need to achieve a high performance, providing food and feed and adapting to variable environmental conditions. Diversification of cropping systems can support ecosystem services and associated biodiversity, but there is little evidence on which temporal field arrangement affects the performance of crop yields (productivity and stability), partly due to a lack of long-term data and appropriate indicators. The objectives of this study were to quantify the effect of cropping system diversification on yield stability, environmental adaptability, and the probability of diversified systems to outperform less diverse cereal-based systems in Europe. Spring and winter cereal yields were analyzed from long-term field experiments from Sweden, Scotland, and France. We investigated diversification through (i) introduction of perennial leys, (ii) increasing the proportion of ley in the rotation, (iii) varying the order in which crops are positioned in the rotation, (iv) introduction of grain legumes, and (v) introduction of cover crops. The results showed that cereal crops within cropping systems incorporating perennial leys outperformed systems without leys in 60–94% of the comparisons with higher probabilities at low fertilizer intensities. The yield stability of oat did not differ, but mean yields were 33% higher, when grown directly after the ley compared to oat grown two years later in the crop sequence under similar management. Durum wheat grown in a cropping system with grain legumes had higher yields in lower-yielding environmental conditions compared to rotations without legumes. Diversification with cover crops did not significantly affect yield stability. We conclude that diverse cropping systems can increase cereal productivity and environmental adaptability and are more likely to outperform less diverse systems especially when introducing perennial forage legumes into arable systems. Effects of diversification on cereal yield stability were inconsistent indicating that higher productivity is achievable without reducing yield variability. These novel findings can support the design of more diverse and high-performing cropping systems.</jats:p>

<jats:title>Abstract</jats:title><jats:p>Soils are the basis of life on land and the ways in which we manage them for crop production, impact their role, functions and quality. Conventional farming uses industrial inputs to a level that is economically justified, whilst organic farming systems avoid mineral fertilizers and synthetic chemical pesticides. This study investigates the long-term effect of organic and conventional farming systems on soil quality. The DOK trial (bio<jats:bold>D</jats:bold>ynamic, bio<jats:bold>O</jats:bold>rganic, <jats:bold>K</jats:bold>onventionell (German for conventional)) running since 1978 in Therwil (CH), compares bioorganic (BIOORG), biodynamic (BIODYN), and conventional (CONFYM) farming systems at two farmyard manure intensities corresponding to 0.7 and 1.4 livestock units per hectare with a purely mineral fertilized system (CONMIN) and an unfertilized control (NOFERT). The treatments in the DOK trial vary in plant protection and receive system-specific organic matter inputs differing in rate and quality. With this work, we revisit the soil organic carbon (SOC) dynamics across 42 years and redefine the previous perception of mainly declining SOC contents after 21 years of organic and conventional management (Fliessbach et al. 2007). After 42 years, we found SOC contents to be increased in BIODYN 1.4 and to a lesser extent also in BIOORG 1.4. CONFYM 1.4 showed stable SOC contents, while systems fertilized with manure of 0.7 livestock units and CONMIN lost SOC. SOC loss was highest in NOFERT. Enhanced biological soil quality under organic and particularly biodynamic management highlights the close link between soil biology and SOC changes. The impact of farming systems on SOC was detectable after 2 decades of continuous management. We conclude that recycling manure at a level of 1.4 livestock units per hectare permits maintenance of SOC levels and that composting manure, as performed in BIODYN 1.4, helps to further increase SOC levels and improve biological soil quality. </jats:p>