Adoption of CA practices: evidence of interdependence in plot level farmer technology choice from rural Tanzania. Bekele Shiferaw
Adoption of Conservation Agriculture Practices (CAPs): Evidence of Interdependence in Plot Level FarmerTechnology Choice from Rural Tanzania Menale Kassie, Bekele Shiferaw, Moti Jaleta, Frank Mmbando et al
Outline• Introduction• Objectives• Novelty• Methodology• Data• What we find (results)• Policy implications
Introduction-1• Declining soil fertility and food insecurity and poverty are major challenges facing African policymakers today• The adoption and use of conservation agriculture practices (CAPs) can help overcome these development challenges• CAPs may offer multiple benefits. But despite substantial initiatives to encourage farmers to invest in CAPs, adoption rates are still low in many countries in SS Africa (Jansen et al. 2006; Wollni et al. 2010; Shiferaw et al. 2011)
Introduction-2• Relatively little empirical work has been done to examine the socioeconomic factors that influence the joint adoption and diffusion of CAPs, especially conservation tillage, organic fertilizers, legume intercropping and legume rotations (Arellanes and Lee 2003).• Understanding the determinants of farmers’ choices of CAPs can provide insights into developing strategies for targeting innovations to accelerate diffusion.
Objectives• Determine the extent of adoption of CAPs among smallholder farmers in SIMLESA project areas in Tanzania• Assess the interdependence between adoption of different CAPs at the farm/plot level• Identify land characteristics, household attributes and market and institutional factors that determine farmer
Why we do this• There is much less research on adoption of multiple CAPs by the same household; little understanding of complementarities and substitution when farmer invest in alternative options.• The effect of social networks, market linkages and institutional variables is less understood: – Market access and value chain linkages – Social capital: kinship and local networks – Government effectiveness in services provision – Biotic and abiotic shocks
Contribution to existing research -2• To the best of our knowledge, no other study has comprehensively and rigorously analyzed the joint adoption of SAPs in the ESA region. The existing studies in Tanzania (e.g., Mbaga-Semgalawe and Folmer 2000; Isham 2002; Tenge et al. 2004) assessed the determinants of partial technology adoption (fertilizer or SWC), which ignored complementarities and/or substitution effects.• There are limited adoption studies on conservation tillage, manure use, legume intercropping and rotations in Africa in general and in Tanzania in particular.
Methodology-1• Jointly analyze the factors that facilitate or impede the probability of adopting CAPs for smallholder farmers in Tanzania• Multivariate probit (MVP) model – There exist household and field level inter-relationships between adoption decisions involving various CAP’s – The choice of technologies adopted more recently by farmers may be partly depend on earlier technology choices --- path dependence – Farm households face technology decision alternatives that may be adopted simultaneously and/or sequentially as complements, substitutes, or supplements
Methodology-2• Unlike the univarite probit model, MVP captures this inter-relationship and path dependence of adoption• Assumes that the unobserved heterogeneity that affects the adoption of one of the CAPs may also affect the choice of other CAPs• Error terms from binary adoption decisions can be correlated
Data• SIMLESA data (2010): – 700 farm households – 1,589 managed plots – 88 villages – 4 districts• Data type: detail household, plot and village information collected• Farming system: maize- legumes
Crop composition: % total cultivated plots allocated to maize and legumes Crops Karatu Mbulu Mvomero Kilosa Total Maize 46.9 52.1 61.0 61.4 54.9 Haricot bean 26.6 47.3 14.0 14.4 26.6 Pigeonpea 26.2 0.0 16.6 12.4 13.6 Other legumes 0.4 0.6 8.4 11.7 5.0 Total 100.0 100.0 100.0 100.0 100.0 Total Plots 542.0 535.0 344.0 555.0
Results: descriptive statistics-1• Definition of Variables and Descriptive Statistics.docxAdoption of CAPs in Tanzania Mean Std. Dev.Legume intercropping Plots received legume intercropping (1 = 0.46 0.50(LI) yes)Conservation tillage (CT) Plots received conservation tillage (1 = yes) 0.11 0.31Soil & water Plots received SWC practice (1 = yes) 0.18 0.39conservation (SWC)Animal manure(AM) Plots received animal manure (1 = yes) 0.23 0.42Improved seeds(IS) Plots received improved seeds (1 = yes) 0.67 0.47Cereal legume Plots received legume crop rotations (1 = 0.17 0.37rotations(CLR) yes)Chemical fertilizer (CF) Plots received chemical fertilizer (1 = yes) 0.04 0.20
Results: descriptive statistics-2 Some explanatory variablesExplanatory variables Mean Std. Dev.Tenure Plot ownership (1 = owned plot; 0 = rented in plot) 0.89 0.31Relatives Number of relatives that a farmer have within a village 8.56 15.96Connections Household has relative in leadership position (1 = yes) 0.26 0.44Market links Number of traders that farmer knows (number) 5.69 7.11Extension Farmers trust the skills of extension agents (1 = yes) 0.61 0.49Pestsdisease Pests and disease risk for crops (1 = yes) 0.64 0.48Salaried Household member has salaried employment (1 = yes) 0.14 0.35Gender Gender of household head (1 = male) 0.88 0.33Insurance Household can rely on govt during crop failure (1 = yes) 0.35 0.50Rainfalindex Rainfall satisfaction index 0.37 0.33Group Participation in farmer coops or association (1 = yes) 0.29 0.46
L TC SW M C anur CR F e LI Empirical Results: Correlation Coefficients for MVP Regression Equations (p-value in parentheses) SAPs Legume Conservation Manure Legume Fertilizer SWC intercropping tillage rotation Conservation tillage 0.21(0.00) Manure 0.35(0.00) 0.10(0.26) Legume rotation -0.3(0.00) -0.16(0.17) -0.39(0.00) Fertilizer -0.03(0.75) -0.24(0.10) -0.07(0.57) -0.15(0.31) SWC 0.03(0.59) 0.36(0.00) 0.11(0.09) 0.01(0.91) -0.07(0.52) -0.03 Seed 0.50(0.00) -0.02(0.81) 0.13(0.00) -0.17(0.00) 0.42(0.00) (0.59)
District level effectsDistricts Conservat Legume Legume SWC Animal Fertilizer Improved ion tillage intercropping rotations manure seedMbulu (+++) (---) (+++) (-) (---)Mvomero (---) (---) (---) (---) (+++) (---)Kilosa (---) (---) (---) (---) (---) (---) Reference is Karatu district
Effect of CAPs on Crop Production Kolmogorov-Smirnov Statistics TestSAP type Distribution 0.2444Legume intercrop (LI) (p = 0.000)*** 1 0.2474Animal manure .8 Cumulative Probability (p = 0.000)*** 0.2762 .6Improved seeds (p = 0.000)*** .4 0.1471Chemical fertilizer (CF) .2 (p = 0.317) 0Soil and water 0.0615 0 1000 2000 3000 Net value of crop productionconservation (SWC) (p = 0.440) Without legume intercrop With legume intercropConservation tillage (CT) 0.1059 Figure 1. Impact of legume intercrop on net value of crop production( 000 TSh/acre) (p = 0.087)*Legume crop rotation 0.0522(LCR) (p = 0.636)
Empirical results: MVP reults-1• Production risk: The probability of adoption of CT, SWC and LI is more common in areas and/or years where rainfall is unreliable (in terms of timelines, amount, and distribution)• Extension - The quality of extension positively influence adoption of CT, SWC, and improved seeds.
Empirical results: MVP reults-2• Markets -The probability of adoption of capital- intensive practices: improved seeds and fertilizer, increase with enhanced value chain linkages (through links with traders).• Rural institutions -Participation in rural institutions (groups, networks) enhances adoption of CAPs (LI, SWC, animal manure and fertilizer).• Public insurance - expectation of public safety nets seems to reduce legume intercropping but increase SWC.• Off-farm income seems to be negatively associated with CAP investment (poverty or specialization
Empirical results: MVP reults-3• Land tenure influences adoption of SWC, CT, & animal manure, which is more common on owner- cultivated plots than on rented in (or borrowed) plots.• Labor - availability of family labor is positively associated with adoption of manure in crop production• Livestock also has positive effect on adoption of improved seeds, fertilizer and legume rotations.
Empirical results: MVP reults-4• Farm equipment ownership has a positive and significant effect on adoption of CT and fertilizer.• Farm size - Households that own less land are more likely to adopt CT, LI, fertilizer and improved seeds; but households with more land practice legume rotations.• Plot characteristics are important determinants of CAP choice. Example - farmers are unlikely to adopt CT, SWC, LI and improved seed on small plots. SWC common on poor soils with gentle/steep slopes .
Conclusion• Plot level interactions are important in identifying suitable CAP combinations for specific environments.• Policies that properly target CAPs based on agro- ecology and are aimed at organizing small-scale farmers into associations, improving market linkages, education, and enhancing skills of civil servants can increase adoption.• Economic benefits from CAPs vary – good practice to identify options that offer relatively quick benefits to farmers.• Future analysis needs to examine the productivity, risk, environmental and welfare implications to particular CAPs and combinations of sustainable agricultural
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