Agronomic and economic benefits of green-waste compost for peri-urban vegetable production: implications for food security

Abstract

A long-term field experiment in western Sydney evaluated the effect of source-separated green-waste (garden organics) compost on peri-urban vegetable crop yields and economic returns, compared to farmer practice. Comparisons were made over 10 vegetable crops between a compost (COMP) treatment (one off application of 125 dry t ha -1 of green waste compost at the start and then every five crops, supplemented with urea when required), a mixed (MIX) treatment (one-off application of 62.5 dry t ha -1 at start and then every five crops, but with inorganic NPK fertiliser inputs for each crop) and a conventional farmer practice (FP). Both COMP and MIX treatments consistently achieved similar or higher yields than FP, but the yield gains were more pronounced for COMP. COMP and MIX treatments delivered benefit-cost ratios of 3.3 and 2.6 respectively compared to FP over the 10 crops, indicating that this system could deliver economic benefits to growers as well as improve soil quality and the environment.Follow up large applications of compost generated more substantial yield increases in responsive vegetable crops and economic benefits. The substantial capsicum crop yield response provided a classic example of closing a crops 'yield gap' through improvements to soil quality with organic inputs, with implications for food security. Both the COMP and MIX treatments lifted the capsicum yield to ~60 t ha -1 , 50% above its perceived maximum potential crop yield for Eastern Australia. The value of larger applications of compost for soil quality, fertiliser savings, crop yield and farm income was apparent.

Do organic fertilizer impact on yield and efficiency of rice farms? Empirical evidence from Bangladesh

“…However, no studies have evaluated how much of these organic fertilizers influence on yield and efficiency of rice production. Previous researches have been done on mulching and composting ( Termorshuizen et al., 2004 ; Jusoh et al., 2013 ), fertilizer management ( Srivastava et al., 2016 ), green wastage usage ( Gong et al., 2018 ; Eldridge et al., 2018 ), rice yield ( Rahman, 2003 ; Thakuria et al., 2009 ; Bäckman et al., 2011 ; Barison and Uphoff, 2011 ; Kabir et al., 2016 ). However, organic fertilizer's impact on rice production and technical efficiency is still a gap in research.…”

The long-term role of organic amendments in addressing soil constraints to production

“…The greatest benefit to SOC and the soil microbial biomass was observed when the starting SOC and N levels were low and when the soils were either neutral or slightly alkaline. Similarly, Eldridge et al (2018) demonstrated large and significant gains in SOC following compost additions. In an 18-year study in paddy rice production, Pan et al (2009) showed a 72 and 103% increase in SOC following annual manure and straw application, respectively.…”

“…Similarly, in a study spanning 28 years, Liu et al (2018) have shown that the annual co-application of horse manure with chemical fertilisers (resulting in an additive nutrient content) can significantly increase the mean yield of corn compared to N, P and potassium (K) fertiliser alone. A study comparing a large oneoff initial application of compost (125 t Ha -1 ), a lower dose of compost (62.5 t Ha -1 ) at two occasions but with annual NPK additions and farmer practice consisting of a lower dose of poultry manure with NPK addition (Eldridge et al 2018) has shown a positive interaction between the compost amendment and the supplied fertilisers. This resulted in greater yield of the vegetable crops in some seasons with the co-application of fertiliser and compost.…”

“…This may be a particularly important strategy where the procurement of chemical fertilisers is limited by their availability or their cost. This aspect was highlighted by Eldridge et al (2018) where cost-benefit ratios of 2.6-3.3 were achieved for the use of compost in vegetable production compared to existing farmer practice in a 10-crop cycle.…”

Sustainable urban agriculture using compost and an open-pollinated maize variety

“…This could be of interest in urban agriculture, as high-64 nutrient urban composts, such as MC, often also exhibit high levels of contaminants and 65 heavy metals, which accumulate along the food chain (Wei et al, 2017). 66 67 While there is substantial work available on mixing feedstock for GWC production with 68 nutrient-rich material, such as manure, food waste or inorganic fertilizers in order to decrease 69 composting time or improve compost quality itself (Reyes-Torres et al, 2018), only recently 70 GWC with subsequent fertilizer combinations were assayed for peri-urban food production, 71 with promising results (Eldridge et al, 2018). However, there are still many issues to address,…”