This sourcebook provides a consensus perspective from the global community of earth observation and carbon experts on methodological issues relating to quantifying the greenhouse gas (GHG) impacts of implementing mitigation activities related to the forest land use in developing countries (REDD+). At current status of negotiation five forest-related activities have been listed to be implemented as mitigation actions by developing countries, namely: reducing emissions from deforestation (which implies a land-use change) and reducing emissions from forest degradation, conservation of forest carbon stocks, sustainable management of forest land, Enhancement of forest carbon stocks (all relating to carbon stock changes and GHG emissions within managed forest land use, including forest expansion on non-forest land). The UNFCCC negotiations and related country submissions on REDD+ have advocated that methodologies and tools become available for estimating emissions and removals from deforestation and forest land management, including forest expansion, with an acceptable level of certainty. Based on the current status of negotiations and UNFCCC approved methodologies, the Sourcebook aims to provide additional explanation, clarification, and methodologies to support REDD+ early actions and readiness mechanisms for building national REDD+ monitoring systems. It complements the Intergovernmental Panel on Climate Change (IPCC) 2006 Guidelines for National Greenhouse Gas Inventories and it is aimed at being fully consistent with this IPCC Guidelines and with the UNFCCC reporting guidelines on annual GHG inventories. The book emphasizes the role of satellite remote sensing as an important tool for monitoring changes in forest cover, provides guidance on how to obtain credible estimates of forest carbon stocks and related changes, and provides clarification on the use of IPCC Guidelines for estimating and reporting GHG emissions and removals from forest lands.
Tag: alley cropping
Nitrogen supply from rotational or spatially zoned inclusion of Leguminosae for sustainable maize production on an acid soil in Indonesia
On acid upland soils in the humid tropics, the combination of high leaching rates and shallow rooted crops may lead to low efficiencies of N use. Sustainability of crop production in this zone depends on either large amounts of external inputs, or on maximising efficiency of the use of local as well as small amounts of external resources. Additional sources of soil organic matter can be obtained by including leguminous cover crops in a rotational system or by spatially zoned systems, with a permanent presence of trees. In view of the high leaching rates, spatially zoned systems with deep-rooted trees may be more effective.Long term soil fertility experiments were started on an Ultisol in Lampung, Sumatera, Indonesia. Data are discussed here for cropping systems based on rotations of maize and leguminous cover crops and for hedgerow intercropping systems (spatially zoned). Maize production in rotations with leguminous cover crops was highest when Mucuna pruriens, Calopogonium mucunoides or C. caeruleum were used. Compared to a grass-weed fallow control, an additional grain yield of 0.5–1 t ha-1 could be obtained. The efficiency of using biomass N was about 0.8 times that of using urea in two split applications. The best results for hedgerow intercropping, a maize yield increase of 1t ha-1 over a control, were obtained with the local tree species Peltophorum dasyrachis
Leucaena-Based Alley Cropping System: An Approach for Reclaiming Degraded Land, Reducing the Use of Inorganic Nitrogen Fertilizer, and Improving Crop Productivity
Alley cropping, an agroforestry system that integrates trees and arable crops, holds the potential to improve both crop yields and soil health. It has been found to be effective for upland crops in many countries of the world. However, the utilization of alley cropping to improve soil health in the terrace ecosystem of Bangladesh is poorly understood. Therefore, this study was undertaken to assess the changes in soil biochemical properties and quantify the cabbage yield under three alley widths of Leucaena leucocephala (3.0, 4.5, and 6.0 m size) and five nitrogen (N) levels [0, 40, 80, 120, and 160 kg N ha−1 (0, 25, 50, 75, and 100% of recommended N rates, respectively) with the addition of pruned materials of L. leucocephala (Ipil-ipil)]. The field experiment was conducted following a split-plot design, where alley width was considered as the main-plot factor and N rate as the sub-plot factor. Within each main plot, the five N rates were replicated thrice. Control plots with similar N doses were applied accordingly without addition of pruned materials to compare the results with alley cropping. Data were collected on the biochemical properties of the soil [soil pH, organic carbon (C), total N, available phosphorus (P), exchangeable potassium (K), microbial biomass C, and biomass N] and the yield of cabbage quantified [edible head weight (kg plant−1) and head yield (t ha−1)] under different alley widths and control. Findings revealed that organic C, total N, available P, exchangeable K, microbial biomass C, and biomass N in the topsoil exhibited maximum values in the L. leucocephala-based alley plot, which is proved to be a possible solution of restoration of degradable land. Additionally, L. leucocephala-based alley cropping improved the soil pH, indicating a potential avenue for more-sustainable land management practices. Results also showed that alley widths and N rates have significant effects on cabbage (Brassica oleracea L. var. capitata) yield. Alley width of 6.0 m along with 100% N provided the highest cabbage yield followed by 75% N in 6.0 m alley, and the control with 100%. The wider alley minimizes tree–crop competition, allowing for optimal cabbage production. These aforementioned results suggest that alley cropping with L. leucocephala is a promising approach to enhance soil fertility and crop productivity in the terrace ecosystem of Bangladesh.
Results of alley cropping experiments with Leucaena leucocephala at the Kenya coast: an example of an appropriate soil conservation (fertility) measure
Alley cropping is a system where arable crops are grown in the interspaces (alleys) between rows of planted trees or woody shrubs which are pruned regularly to prevent shading and to provide manure and mulch to the crop. Alley cropping spacing trials were designed at Mtwapa Agroforestry/Energy Centre to establish trends in crop and tree performance under various planting arrangements and densities. Also giving of information on which tree species, which spacings of the trees, and which management practices to use to give maximum economic benefits. The results show that alley cropping with leucaena leads to reduced nutrient loss and is a soil conservation measure
Soil moisture changes and maize productivity under alley cropping with leucaena and flemingia hedgerows at Chalimbana, near Lusaka, Zambia.
Soil moisture changes and maize yield were studied in 2-year-old alleys of Leucaena leucocephala and Flemingia macrophylla at Chalimbana, Zambia. Field tensiometers were installed at 15, 30 and 45 cm depth, in fertilizer and unfertilized alleys within the double hedgerows, and the first, second and third rows of maize, and were monitored throughout one maize growing season in 1989/1990. In general, maize growth (indicated by height and dry matter measured at roughly fortnightly interval) was higher (P <0.01) in fertilized alleys than in unfertilized alleys, and there were no differences between Leucaena and Flemingia alleys. In both fertilized and unfertilized alleys, the maize plants were 20% shorter (P <0.01) in the first row (nearer the hedgerows) than in the second and third maize rows. Maize dry matter yield was 30% more (P<0.01) in unfertilized Flemingia alleys than in corresponding Leucaena alleys. The grain yield was similar in the fertilized alleys of Leucaena and Flemingia. However, in unfertilized alleys, the grain yield in Flemingia alloys was 50% more than that of the corresponding Leucaena alleys. The fertilized alleys produced twice as much grain as unfertilized alleys when hedgerow prunings were added to the plots. The prunings as a source of nutrient did not appear to have any noticeable effect on crop productivity. The soil moisture content under both Leucaena and Flemingia hedgerow was higher than under the maize rows in the alleys throughout the growing season. The study shows that, under conditions of low fertility and no addition of fertilizers, Leucaena is twice as competitive, as Flemingia for soil resources, and reduces yield of alley-cropped maize from 2.2 t ha1 to 0.7 t ha1. If, however, fertilizer is added, there are no short-term differences between the two hedgerow species.
Surveying farmers’ agroforestry plots: experiences in evaluating alley-cropping and tree border technologies in western Kenya
Evaluation of existing on-farm agroforestry plots should provide useful supplementary information for the design of improved agroforestry systems, in both research and development projects. Such evaluation has been little used, however, largely due to the methodological difficulties of surveying highly variable on-farm plots, and difficulties in identifying key variables for measurement. This paper describes a set of methods and tools used in evaluating plots of alley-cropping and tree borders around crop fields established by farmers working with the CARE Agroforestry Extension Project in western Kenya. Details of survey design, sampling, and implementation are discussed, and suggestions made for carrying out agroforestry surveys in other projects. A condensed version of the questionnaire is appended.
Results of alley cropping experiments with Leucaena leucocephala and Zea mays at the Kenya Coast
This paper covers the 1982 research on hedgerow intercropping which was initiated with 8 different tree species at the Mtwapa agricultural research station to identify ways to improve these yields. The major objectives of the trials were to get information on best tree species, planting spacing, and management practices to give maximum economic benefits to local small-scale farmers
Rooting depth in cropping systems in the humid tropics in relation to nutrient use efficiency
A simple model is presented for calculating the rooting depth of a crop or crop combination required to intercept leaching nutrients for different climatic and soil conditions. Important parameters in this model are the amount of water moving through the soil, which depends on excess of rainfall over evapotranspiration, and the apparent adsorption constant, which depends on the nutrient and soil type involved. Calculations for three time patterns of nutrient supply in relation to nutrient demand show moderate effects of the degree of synchronization on rooting depth required if a high interception fraction is desired. In shifting cultivation systems a deep-rooted fallow vegetation can recover nutrients leached to the subsoil during the cropping phase. The simple leaching model can indicate the combinations of climate zone and apparent adsorption constant for which such interception is possible. It appears that recovery of leached nitrate is only possible in the subhumid zone. In the humid tropics the continuous presence of a deep root system as part of the crop combination on the field is necessary to use nitrogen efficiently, except when acid soil conditions keep all nitrogen in the ammonium form or when an almost ideal synchronization exists of nitrogen supply and demand during the growing season. Some data are discussed on the root distribution of food crops and on the possibilities to establish a “safety-net” under the crops grown in alleys between deep-rooted hedgerow trees.