No abstract

Grain legumes have declined to a low base in many regions of intensified agriculture yet have the potential both to safeguard food security and satisfy rising ethical demands from food consumers. Here, the scope for legume expansion is examined in a long‐established agricultural region in eastern Scotland where grain legumes declined to <0.3% of cropped area in the 1930s and now vary around 1%. Data from the EU's Integrated Administrative and Control System (IACS) were combined with national agricultural survey to resolve uncertainties over possible restrictions to expansion following 20th‐century intensification. The grain legumes, peas and beans for animal and human consumption, were found to occupy six crop‐grass systems covering a wide range of agronomic input and geographical location. The phase of agricultural intensification between 1950 and 1990 had widened rather than restricted the systems in which they occur and could expand. Moreover, the diversity of the crop‐grass systems provides scope for complementary expansion of several products such as beans for aquaculture, pulses for human consumption, and peas for stockfeed without diminishing the areas of the most profitable crops. Among crop systems, N inputs following 20% legume inclusion would fall from the current 178 to 140 kg/ha (78.6%) at the high‐input end of the range and from 92 to 71 kg/ha (77.0%) at the low‐input end. Further reductions to 50%–60% of the existing N input to intensive crop sequences were estimated assuming a residual fixed nitrogen of 50–75 kg/ha and legume inclusion of 33%. Legume expansion would also bring a range of environmental benefits across all crop‐grass systems. While analysis using IACS brought many insights, major limitations to estimating national N‐balances were identified in lack of data on residual N following legumes, in imported animal feed and in the contribution of forage legumes to grassland.

Background: There is an urgent need to ensure that food production is maintained in response to either a reduction in use or lack of availability of natural resources. To this end, several strategies have been investigated to determine which agronomic approaches may improve crop yields under conditions of reduced water and/or nutrients provision, with special attention upon nitrogen (N) and phosphorus (P). New technologies and practices have been developed for key commercial crops, such as tomatoes. However, few of these are widely adopted in the field and evidence of their value in this production setting is limited. Methods: This protocol sets out a systematic map methodology that aims to provide a coherent synthesis of the available evidence among the literature on the techniques and management approaches that may ensure the productivity of field-grown tomatoes under conditions of water-, N-and/or P-deficits, either as single or combined stresses. To conduct the literature search, a search strategy was produced to define the scope of the systematic map and to allow reproducibility of the approach. A list of published and unpublished sources of literature were selected and a preliminary trial identified best-fit-for-purpose search-terms and-strings. A literature screening process was set with consistency checks amongst reviewers at the title, abstract and full text screening stages. A series of eligibility criteria were defined to ensure objectivity and consistency in the selection of studies that are best suited to address the research question of the systematic map. In addition, a coding strategy was designed to set the means for metadata extraction out from the literature for review. A drafted structured questionnaire will serve as the base for collating the meta-data to produce a database where variables will be queried for the evidence synthesis. This work is expected to inform stakeholders, researchers and policy makers regarding the extent and nature of the existing evidence base, and so serve as a basis by-which specific approaches may be highlighted as potential focal-areas in future.

Background Agriculture is facing an unprecedented challenge in having to reduce its environmental footprint whilst ensuring food security to an ever-growing global population. Towards this end, several strategies have been investigated and implemented to help maintain or improve crop yield under reduced water and/or nutrient provision for key commercial commodities such as tomatoes. Despite the high commercial, nutritional, and food-cultural value, there is no synthesis of evidence regarding yield maintenance of tomato (as a model crop) under resource-deficit. This systematic map therefore provides an overview of the evidence that exists on the effectiveness of techniques and management approaches aimed at improving the productivity of field-grown tomatoes under conditions of water-, nitrogen- (N) and/or phosphorus (P)-deficit. Methods Following the published map protocol, systematic searches of peer reviewed- and grey-literature were conducted using research publication databases, and specialist websites. A total of 14,377 unique articles were identified as potentially relevant to our research question, of which 927 were screened at the full-text level. Of that subset, 291 articles met all the pre-defined eligibility criteria. Basic information and meta-data on the interventions reported were recorded for these articles and a systematic map was compiled with the extracted data. Results The articles included in the systematic map database were used to identify several significant points including: (1) from the year 2000, the number of articles investigating strategies to improve field-grown tomato yield under conditions of water and/or nutrient deficit follows an upward trend; (2) large evidence bases (> 50%) originated from the United States, India, and Italy; (3) most studies addressed water alone as a resource (49%), with only 18% of studies focussing on N and 4% on P alone. Only 4% of records assessed all three resources simultaneously; (4) most evidence (77%) aims to improve resource use-efficiency via either irrigation, fertilisation, or crop and soil management strategies; and (5) different geographical regions appear to focus on different groups of interventions. Conclusions This systematic map identifies a range of interventions that have been successfully implemented in fields to improve the yield of commercial tomatoes under conditions of water, N and/or P deficit. However, only half of the relevant literature reported evidence on more than one intervention, which highlights the need for more integrated approaches to assess multiple interventions to adapt to deficits of key-resources simultaneously. In addition, the use of ‘techno-chemical’, ‘breeding and genetic’ and ‘computational’ interventions are only reported in a small number of records (< 8% of the gathered evidence). Hence, these interventions may also be considered as subjects to prioritise in future funding strategies.

No abstract