A Novel Technology for Processing Urban Waste Compost as a Fast-Releasing Nitrogen Source to Improve Soil Properties and Broccoli and Lettuce Production

Abstract Purpose: This study evaluated nitrogen (N) mineralization dynamics in three soils after the addition of heat-treated urban waste amendments or urban waste compost (UWC). The effects of UWC and urea on soil properties and broccoli and lettuce production were compared. Methods: The first N mineralization experiment was conducted in a factorial arrangement (4 × 3), as a randomized complete block design (RCBD), with three replicates. Four UWC doses: 12.5, 25.0, 37.5, and 50.0 mg dm-3 were applied to three soils: sandy Ustoxic Quartzipsamment (QS), intermediate-texture red Ultisol (US), and clayey red Oxisol (OS), during eight incubation periods (0, 7, 14, 28, 42, 56, 70, and 84 days). In the second experiment, the effects of UWC and urea fertilizer on soil properties were compared. The growth of broccoli and lettuce plants was evaluated (experiments 3 and 4). The treatments (Experiments 2–4) followed a factorial arrangement (4 × 2; RCBD; three replicates), using OS soil. Four N doses (as for experiment 1) were combined with two N sources (UWC and urea). Results: The processed UWC application proportionally increased the N mineralization rate by 72% in QS, 54% in US, and 66% in OS. Furthermore, UWC application enhanced soil properties (pH and nutrient availability), compared with urea fertilizer, and improved N uptake, resulting in higher fresh biomass production in broccoli and lettuce plants (50.0 and 37.5 mg dm-3, respectively). Conclusions: Our findings suggest that heat-treated UWC is an economical, viable, and efficient fertilizer to improve soil properties and short-cycle vegetable crop productivity.

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Using manure for improving nitrogen fertilization and maize yield

Experimental Agriculture ◽

10.1017/s0014479720000393 ◽

2020 ◽

Vol 56 (6) ◽

pp. 901-914

Author(s):

Xucun Jia ◽

Qinglong Yang ◽

Shu-Ting Dong ◽

Ji-Wang Zhang ◽

Bin Zhao ◽

...

Keyword(s):

Grain Yield ◽

Soil Properties ◽

Nitrogen Source ◽

Diversity Index ◽

Nitrogen Loss ◽

Soil Aggregates ◽

Chemical Fertilizer ◽

Cattle Manure ◽

Control Treatment ◽

Total N

AbstractManure and chemical fertilizers have different effects on soil properties, the nitrogen cycle, and crop yield. This study aimed to investigate the effects of different fertilizer applications under the same N input on soil physicochemical properties and soil bacterial communities and to explain the contributions of soil properties to grain yield. Manure substitution of chemical fertilizer was conducted in leaching monitoring systems. The study began in 2009 and sampling was carried out in 2014 and 2016. Three fertilizer treatments with the same total N, P, and K application rates and one control treatment were designed as follows: (1) CK, without nitrogen fertilizer; (2) 100%U, whole nitrogen coming from urea; (3) 100%M, whole nitrogen coming from composted cattle manure; and (4) 50%U + 50%M, half nitrogen from composted cattle manure and half nitrogen from urea. Soil organic carbon (SOC) content was positively correlated with total N (TN), NO3−–N, and NH4+–N contents, the mean weight diameter of soil aggregates, and the Shannon diversity index of bacteria, whereas SOC content was not significantly correlated with grain yield. NO3−–N content was positively correlated with grain yield. Substituting half the amount of chemical fertilizer with manure as a nitrogen source improved soil stability, increased bacterial diversity, and enhanced nitrogen supply, while reducing nitrogen loss from ammonia volatilization and nitrogen leaching. Substituting half the amount of chemical fertilizer with manure as a nitrogen source was a more sustainable way to increase grain yield through a sustainable nitrate supply and to reduce N loss.

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