Exploring GLDC Crops in NRM Evidence for Farming Systems

NRM evidence for inclusion of GLDC crops in NRM evidence for inclusion of GLDC crops in farming farming systems systems Reference Group Meeting, Reference Group Meeting, 2 Dec 2020 2 Dec 2020 Welcome and Introductions

NRM evidence for inclusion of GLDC crops in farming systems NRM evidence for inclusion of GLDC crops in farming systems Reference group meeting II Reference group meeting II A preview of reference meeting I A preview of reference meeting I Agenda for reference meeting II: 2 December 2020 An update on data extraction Results from preliminary analysis Outlook/next steps In the previous meeting we discussed review protocol, including: Objectives of the review Research questions Indicators of NRM Potential moderators Search strategy Selection and screening Critical appraisal and data extraction Elements of the database Illustration of results Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems Research questions Research questions Primary research question Primary research question What is the evidence for the role of GLDC in contributing to NRM? Secondary research questions Secondary research questions What kind of indicators are commonly used as measures NRM for GLDC in dryland and sub-humid tropics in Africa and South Asia? What happens when farmers adopt or do not include GLDC in farming systems? When farmers start to plant these legumes or cereals; move from these crops; move from traditional varieties to improved varieties; move from one type of legume or cereal to another? What influence has management practices on the indicators on NMR evidence identified? What are the major gaps in the evidence base? Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems Indicators Indicators Category Category Indicators of direction (of change) Indicators of direction (of change) Indicator of (change) impact Indicator of (change) impact Productivity Net primary productivity Land equivalent ratio, crop yield (grain, biomass) Land Carbon sequestration, organic matter, Soil organic carbon, total N, available P, N fixed, management Water biomass, biol. N fixation, soil respiration Infiltration rate, water use efficiency, run- microbial biomass carbon Soil moisture content management Environmental off, erosion control N2O flux, CO2 flux, soil respiration, nutrient loss, phytoremediation Species diversity indices; microbial activity, Greenhouse gas (GHG) emissions, GHG intensity quality Biodiversity Changes in population of macro-fauna, AMF community microbial diversity Natural enemies, plant damage, pest System Competitiveness of crops, yield stability, tolerance to resilience abundance, weed density, weed biomass drought, pest pressure Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems Potential moderators Potential moderators Biophysical (site characteristics) Biophysical (site characteristics) Management Management (interventions) (interventions) Elevation Cropping system Rainfall Tillage Soil type Inorganic fertilizer Soil texture (clay content) Manure Soil organic carbon Residue management Soil pH Irrigation regimes Management of weeds, pests and diseases Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems NRM evidence for inclusion of GLDC crops in farming systems Data extraction Data extraction Number of articles form database searches (N = X) Number of documents from other searches (N = X) Identification A comprehensive search across bibliographic bibliographic Full text screening completed for 825 publications Data extracted from 462 Data presented in figures was extracted using WebPlotDigitizer So far, 334 publications qualify for systematic review and 147 qualify for meta-analysis Publications consist of 454 articles, 5 book chapters, 1 review article, 1 note and 1 poster. Web of Science 1214 Scopus ProQuest Websites Experts Reference list 7 771 9330 databases and grey literature grey literature # of documents after removig duplicates N =11306 A comprehensive search across Search strategy Search strategy Screening # of documents after appraisal of title and abstract, N = 1875 Documents excluded (N = 9438) databases and Full text appraisal is still on going Documents excluded and reasons Eligibility Exclusion criteria Questionable journal Not accessible Double publication Documents included for review so far, N = 462 Inclusion Systematic review So far, N = 334 Type of review Meta-analysis So far, N = 147

NRM evidence for inclusion of GLDC crops in farming systems Comparing where research on GLDC was conducted Comparing where research on GLDC was conducted Studies were spread widely across 33 countries (302 studies in Africa, 159 in South Asia) Countries with the most studies were India (25%), Nigeria (15%), Ghana (7%), Ethiopia (6%) and Kenya (5%). In South Asia, most of the studies were from India (74%) followed by Pakistan (19%) In Africa, over half of the studies were from west Africa (59%); 27% were from eastern Africa. Out of the 64 countries admissible for selection, so far no studies found in 31 countries. What are possible reasons why these countries were not captured in the search? 120 Africa, n = 302 100 South Asia, n = 159 80 No. of studies Some countries show moderate research effort while others have few studies that met the selection criteria. These differences are large and highlight a gap, considering that the studies included cover the period from 1975 to 2020 60 40 20 0 Nigeria Algeria Benin Eritrea Mozambique Sri Lanka Ethiopia Senegal Morocco Bangladesh Kenya Burkina Faso Zimbabwe Botswana Malawi DRC India Nepal Ghana Mali Uganda Rwanda Pakistan Ghana C te d Ivoire Niger Egypt Tanzania Sudan Sierra Leone Somalia Cameroon South Africa Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems Nature of reviewed literature Nature of reviewed literature Two types of study Two types of study designs designs Types of settings Types of settings Field trials that test the performance or response of specific GLDC. These describe the impact of GLDC on indicators relevant to this study. Observational studies on the effect of GLDC. They report status of an indicator before and after, or in a GLDC compared to non-GLDC Inclusion of GLDC takes place in a range of settings Most studies were conducted at research stations (74%, n=472), 24% on farmers fields; the reminder did not state the type of trial Only three studies mentioned whether they were researcher- or farmer-managed. GLDC are grown as sole crops within a season (64%) or continuously (2%); as intercrops (16%), in rotations (12%), or with trees (3%) A small proportion are grown on rested (fallow) land (1%) or for green manure (1%). 70 No. of studies = 472 Poportion of studies (%) 60 50 40 30 20 10 0 Crop rotaion manure cropping cropping Agroforestry Fallow Continuous Green Inter- Sole Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems GLDC grown as a main crop GLDC grown as a main crop GLDC grown as a companion GLDC grown as a companion crop crop Cowpea, pearl millet, sorghum and soybean are the leading crops for studies conducted in Africa Soybean, sorghum, chickpea and groundnuts are the leading crops for studies conducted in south Asia Africa (n = 99) 35 South Asia (n = 58) 30 25 20 Number of studies 15 10 5 0 Finger millet Lentil Soybean Cowpea Peal millet Common bean Chickpea Groundnut Pigeon pea Sorghum Africa (n = 324) 80 South Asia (n = 170) 70 60 50 Number of studies 40 Mainly in as intercrops or in rotation 30 20 10 0 Finger millet Lentil Soybean Cowpea Pearl millet Pigeon pea Common bean Groundnut Chickpea Sorghum The proportion of publications reporting on different GLDC crops in Africa and South Asia. Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems Effects of GLDC on NRM indicators Effects of GLDC on NRM indicators Research continues to focus on Research continues to focus on yields yields Productivity Most publications assessed outcomes associated with productivity (Africa 72%, South Asia 69%) as compared to land management (Africa 14%, South Asia 17%), or other indicators of NRM A small number (5) of publications from South Asia examined outcomes on environmental quality There is need to check this bias (towards yield) by assessing other systematic reviews and meta- analysis that synthesis literature on GLDC. If confirmed, then we conclude that the focus on yield is prevalent in primary studies, and in existing research synthesis. Land management System resilience Water management Biological N fixation Biodiversity Environmental quality 0 10 20 30 40 50 60 70 80 South Asia (n = 205) Africa (n = 371) Proportion of publications reporting different indicators of NRM in Africa and South Asia. Categories are non-exclusive; some studies reported more than one indicator. Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems Effects of GLDC on NRM indicators Effects of GLDC on NRM indicators 25 Evidence for carbon sequestration Evidence for carbon sequestration Organic carbon (n = 52) Biomass (n = 78) The coverage and evidence for the impact of GLDC on carbon sequestration was diverse, and include studies that report SOC, biomass of crops and stover SOC reported in 52 publications for studies conducted in 10 countries Biomass reported in 78 publications for studies conducted in 19 countries Stover reported in 66 publications for studies conducted in 14 countries Biomass produced by GLDC can add to SOC if crop residues are retained in the field or removed as fodder and retuned back as manure or compost. 20 15 10 Number of studies 5 0 Nigeria Ethiopia Kenya Burkina Faso C te d Ivoire Bangladesh Morocco India Mozambique Senegal Ghana Uganda Mali Niger Pakistan Tanzania Sudan South Africa Cameroon Sierra Leone Proportion of publications reporting SOC and biomass in for studies conducted in different countries. Categories are non-exclusive. Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems Effects of GLDC on NRM indicators Effects of GLDC on NRM indicators 25 Evidence for biological nitrogen fixation Evidence for biological nitrogen fixation Amount of nitrogen fixed by grain legumes reported in 66 publication for studies conducted in 14 countries Stover (n = 66) N fixed (n = 26) 20 Number of studies 15 10 Potential Potential for nutrient cycling for nutrient cycling Stover reported in 26 publications for studies conducted in 14 countries Nitrogen fixation and nutrient cycling via stover can contribute to building more sustainable agroecosystems and increased yield 5 0 Nigeria Ethiopia Burkina Faso Kenya Bangladesh Botswana Malawi India Mozambique Senegal Ghana Mali Uganda Niger Pakistan Tanzania Egypt Sudan Cameroon South Africa Proportion of publications reporting amount of stover or nitrogen fixed in for studies conducted in different countries. Reference group meeting II 2 December 2020

NRM evidence for inclusion of GLDC crops in farming systems OUTLOOK OUTLOOK OUTPUTS OUTPUTS Completion of data extraction of data from remaining papers Search on list of websites from relevant organizations for relevant publications Create an illustrative theory of (change) how inclusion of GLDC may bring about change in NRM Statistical analysis and synthesis of results Independence of observations/data-points Publication bias and sensitivity analyses Illustration of results etc. Draft manuscripts (a systematic review and a meta- analysis) 1. A systematic review methodology will be used review NRM evidence from both peer reviewed publications and grey literature. The systematic review will identify, select review will identify, select and NRM NRM evidence evidence. The systematic review will also identify gaps in research and knowledge. The systematic and synthesis all available synthesis all available 2. A meta-analysis will be applied to data means of treatment and control are available. A meta- analysis is statistical procedure for combining data from multiple studies to come up with an overall trend. The The meta meta- -analysis will assess the strength analysis will assess the strength and direction of NRM evidence present in the and direction of NRM evidence present in the literature, literature, and the conditions under which the trend and the conditions under which the trend is negative, positive, or no effect is negative, positive, or no effect Reference group meeting II 2 December 2020