Climate-Smart Agriculture (CSA) within the Feed the Future Project Portfolio of USAID-Zambia: A CCAFS Deep Dive Review

As part of a global effort that will inform how Feed the Future tracks CSA across the 19 focus countries (plus aligned) the CCAFS and USAID/BFS team selected 5 to carry out a deeper analysis of their portfolio. A visit in May 2015 by staff from CCAFS and USAID-BFS Washington to the Zambia Mission provided an opportunity to identify and discuss CSA-related activities within the country and the USAID zone of influence (ZOI). The five-day visit included a series of meetings with Mission staff, implementing partners of Feed the Future projects, agency personnel of the Government of Zambia, and the FAO-Zambia CSA specialist. The discussions were preceded by a document review of projects in the Feed the Future portfolio, shared in advance of the visit by the Mission, and other agriculture and climate change information available on the web. This report outlines key findings of the visit and suggests ways in which CSA can be further integrated into upcoming Feed the Future programming in Zambia. Although climate change has been a key theme in FtF, considerations are under way for CSA being an explicit cross-cutting theme. Five countries were selected for visits. Results from these inquiries will inform how FtF tracks CSA across the 19 focus countries, plus aligned countries

CCAFS Deep Dive Assessment of Climate-Smart Agriculture (CSA) in the Feed the Future Portfolio in Senegal

As part of a global effort that will inform how Feed the Future tracks CSA across the 19 focus countries (plus aligned) the CCAFS and USAID/BFS team selected 5 to carry out a deeper analysis of their portfolio. In July 2015, CCAFS’ visit to the USAID Senegal mission provided an opportunity to identify and discuss CSA-related activities within the country and the USAID zone of influence (ZOI) highlighting the importance of addressing the effects of climate change in the agricultural sector and the current and potential benefits of Feed the Future’s presence for climate resilience. The visit included meetings with USAID Mission staff, Feed the Future implementing partners, and three government agencies. The process also included the review of Feed the Future strategy and project documents, as well as a limited external literature review. This report outlines the key findings of the visit and highlights some ways in which CSA approaches can be further incorporated into the Mission’s future programming

Stem, root, and older leaf N:P ratios are more responsive indicators of soil nutrient availability than new foliage

Author Posting. © Ecological Society of America, 2014. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 95 (2014): 2062–2068, doi:10.1890/13-1671.1.Foliar nitrogen to phosphorus (N:P) ratios are widely used to indicate soil nutrient availability and limitation, but the foliar ratios of woody plants have proven more complicated to interpret than ratios from whole biomass of herbaceous species. This may be related to tissues in woody species acting as nutrient reservoirs during active growth, allowing maintenance of optimal N:P ratios in recently produced, fully expanded leaves (i.e., “new” leaves, the most commonly sampled tissue). Here we address the hypothesis that N:P ratios of newly expanded leaves are less sensitive indicators of soil nutrient availability than are other tissue types in woody plants. Seedlings of five naturally established tree species were harvested from plots receiving two years of fertilizer treatments in a lowland tropical forest in the Republic of Panama. Nutrient concentrations were determined in new leaves, old leaves, stems, and roots. For stems and roots, N:P ratios increased after N addition and decreased after P addition, and trends were consistent across all five species. Older leaves also showed strong responses to N and P addition, and trends were consistent for four of five species. In comparison, overall N:P ratio responses in new leaves were more variable across species. These results indicate that the N:P ratios of stems, roots, and older leaves are more responsive indicators of soil nutrient availability than are those of new leaves. Testing the generality of this result could improve the use of tissue nutrient ratios as indices of soil nutrient availability in woody plants.Data are from Santiago et al. (2012), which was supported by a grant from the Andrew W. Mellon Foundation to S. J. Wright, a Smithsonian Institute Scholarly Studies grant to S. J. Wright and J. B. Yavitt, and a University of California Regent’s Faculty Fellowship to L. S. Santiago. L. A. Schreeg was partially supported through a Marine Biological Laboratory-Brown University SEED grant to Z. Cardon, S. Porder, and L. A. Schreeg

Nutrient-specific solubility patterns of leaf litter across 41 lowland tropical woody species

Abstract. Leaching is a mechanism for the release of nutrients from litter or senesced leaves that can drive interactions among plants, microbes, and soil. Although leaching is well established in conceptual models of litter decomposition, potential nutrient solubility of mineral elements from recently senesced litter has seldom been quantified. Using a standardized extraction (1:50 litter-to-water ratio and four-hour extraction) and recently senesced leaf litter of 41 tropical tree and liana species, we investigated how solubility varies among elements, and whether the solubility of elements could be predicted by litter traits (e.g., lignin, total element concentrations). In addition, we investigated nutrient forms (i.e., inorganic and organic) and ratios in leachate. Water-soluble elements per unit litter mass were strongly predicted by total initial litter element concentrations for potassium (K; r 2 ¼ 0.79), sodium (Na; r 2 ¼ 0.51) and phosphorus (P; r 2 ¼ 0.66), while a significant but weaker positive relationship was found for nitrogen (N; r 2 ¼ 0.36). There was no significant relationship for carbon (C) or calcium (Ca). Element-specific solubility varied markedly. On average 100% of total K, 35% of total P, 28% of total Na, 5% of total N, 4% of total Ca, and 3% of total C were soluble. For soluble P, 90% was inorganic orthophosphate. The high solubility of K, Na, and P as inorganic orthophosphate suggests that these nutrients can become rapidly available to litter microbes with no metabolic cost. Few common predictors of decomposition rates were correlated with element solubility, although soluble C (milligrams per gram of litter) was negatively related to lignin content (r 2 ¼ 0.19; P , 0.004). Solubility of elements was linked within a species: when a species ranked high in the soluble fraction of one element, it also ranked high in the solubility of other elements. Overall nutrient-specific patterns of solubility from recently senesced litter emphasize that litter elements cannot be treated equally in our conceptual and empirical models of decomposition. The relatively high potential solubility of P as orthophosphate from fresh litter advances our understanding of ecological stoichiometric ratios and nutrient bioavailability in tropical forests

Assessing Nutrient Limitation in Complex Forested Ecosystems : Alternatives to Large-Scale Fertilization Experiments

Quantifying nutrient limitation of primary productivity is a fundamental task of terrestrial ecosystem ecology, but in a high carbon dioxide environment it is even more critical that we understand potential nutrient constraints on plant growth. Ecologists often manipulate nutrients with fertilizer to assess nutrient limitation, yet for a variety of reasons, nutrient fertilization experiments are either impractical or incapable of resolving ecosystem responses to some global changes. The challenges of conducting large, in situ fertilization experiments are magnified in forests, especially the high-diversity forests common throughout the lowland tropics. A number of methods, including fertilization experiments, could be seen as tools in a toolbox that ecologists may use to attempt to assess nutrient limitation, but there has been no compilation or synthetic discussion of those methods in the literature. Here, we group these methods into one of three categories (indicators of soil nutrient supply, organismal indicators of nutrient limitation, and lab-based experiments and nutrient depletions), and discuss some of the strengths and limitations of each. Next, using a case study, we compare nutrient limitation assessed using these methods to results obtained using large-scale fertilizations across the Hawaiian Archipelago. We then explore the application of these methods in high-diversity tropical forests. In the end, we suggest that, although no single method is likely to predict nutrient limitation in all ecosystems and at all scales, by simultaneously utilizing a number of the methods we describe, investigators may begin to understand nutrient limitation in complex and diverse ecosystems such as tropical forests. In combination, these methods represent our best hope for understanding nutrient constraints on the global carbon cycle, especially in tropical forest ecosystems

Appendix B. A figure showing the stoichiometry of soluble C, phosphate-P, and total N, on a litter mass basis.

A figure showing the stoichiometry of soluble C, phosphate-P, and total N, on a litter mass basis

Supplement 1. Initial litter quality and water-soluble element data by species.

<h2>File List</h2><div> <p><a href="supplemental_litter_leaching_20120822.csv">supplemental_litter_leaching_20120822.csv</a> (md5: a5b18924aff40de97816e3a41342150a) </p> </div><h2>Description</h2><div> <p>The file contains initial litter quality and water soluble element data listed by species. Initial litter quality data was determined by grinding and homogenizing 10 g of litter (petioles removed) per species. Water soluble element and pH data show the average of three water extracts per species, with the exception of inorganic N that only had two replicates per species. Water soluble element and pH data are from 4 h extracts. All data expressed on a litter mass basis use oven-dried (60°C) mass.</p> <p>Columns are as follows:</p> <p>1. Species. Species are referenced by species code. See <a href="appendix-A.htm">Appendix A</a> for species names.</p> <p>2. Total Al concentration in the initial litter expressed as mg Al/g litter.</p> <p>3. Total C concentration in the initial litter expressed as mg C/g litter.</p> <p>4. Total Ca concentration in the initial litter expressed as mg Ca/g litter.</p> <p>5. Total K concentration in the initial litter expressed as mg K/g litter.</p> <p>6. Total Mg concentration in the initial litter expressed as mg Mg/g litter.</p> <p>7. Total N concentration in the initial litter expressed as mg N/g litter.</p> <p>8. Total Na concentration in the initial litter expressed as mg Na/g litter.</p> <p>9. Total P concentration in the initial litter expressed as mg P/g litter.</p> <p>10. Percent lignin in initial litter.</p> <p>11. Water extractable Al expressed as extracted mg Al/g litter.</p> <p>12. Dissolved organic carbon expressed as extracted mg C/g litter.</p> <p>13. Water extractable Ca expressed as extracted mg Ca/g litter.</p> <p>14. Water extractable K expressed as extracted mg K/g litter.</p> <p>15. Water extractable Mg expressed as extracted mg Mg/g litter.</p> <p>16. Water extractable Na expressed as extracted mg Na/g litter.</p> <p>17. Water extractable total N (inorganic + organic N) expressed as extracted mg N/g litter.</p> <p>18. Water extractable N-NH4 expressed as extracted mg N/g litter.</p> <p>19. Water extractable N-NO3 expressed as extracted mg N/g litter.</p> <p>20. Water extractable molybdate reactive phosphorus (commonly referred to as orthophosphate) expressed as extracted mg P/g litter.</p> <p>21. Water extractable total P (inorganic + organic) expressed as extracted mg P/g litter.</p> <p>22. Leachate pH.</p> <p>Missing data</p> <p>NA indicates ‘not available’.</p> </div