Abstract
No-till farming and manure application are means of storing carbon in soil and increasing soil quality. However, the organic fertilization of no-till soils may sustain subtropical agroecosystems for only a limited period until the soil quality declines. The C, N, P, and other nutrient cycles are perturbed due to the nutrient imbalance in manures and their application on the soil surface, which poses a risk for nutrient dispersion into the environment. Long-term N-based manure application also impacts the apparent nutrient recovery (ANR) by crops and, hence, the crop quality. Our objective was to monitor changes in soil quality and to measure nutrient recovery from N-based organic fertilization in a Brazilian agroecosystem. A long-term experiment was established in May 2004 on Typic Hapludalf soil in Southern Brazil. The experiment comprised two periods: 2004–2009 and 2009–2020. The treatments were unfertilized (control), pig slurry, pig deep litter (swine manure and rice husk), cattle slurry, and mineral fertilizer (urea, triple superphosphate, and K chloride). Grain and cover crops were grown. The maize grain yield and oat biomass were used as indicators of productivity. The application of cattle slurry, pig deep litter, and pig slurry increased the grain production by 20% on average compared to mineral fertilization. Organic manuring increased the soil pH by up to one unit, while urea acidified the soil. The highest crop yields were obtained with pig deep litter, which increased the levels of P, K, Ca, Mg, and C in the soil test. Pig deep litter showed the highest N-ANR for the aboveground part of the plants. The ANRs for P, K, Ca, and Mg were also highest when pig slurry had been applied. The ANR values for the micronutrients varied widely among the organic sources but indicated large marginal offtake gains compared to mineral fertilization. The N-based fertilization with animal manures increased the rate of nutrient uptake by plants but led to an accumulation of nutrients in the soil, threatening the sustainability of the system. Manure applications must be monitored regularly to avoid the accumulation of nutrients that could impair the soil quality and become an environmental problem in the future.
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Claims 7
Claim · model-written summary
Animal manures increased grain production by 20% on average compared with mineral fertilization.
- Treatment
- cattle slurry, pig deep litter, and pig slurrye0
- Outcome
- grain productione0
- Direction
- increasede0
- Value
- 20%e0
- Comparator
- mineral fertilizatione0
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The maize grain yield and oat biomass were used as indicators of productivity. The application of cattle slurry, pig deep litter, and pig slurry increased the grain production by 20% on average compared to mineral fertilization.”
Claim · model-written summary
Pig deep litter gave the highest crop yields.
Not reportedTaxonComparator
Verbatim
e0“The highest crop yields were obtained with pig deep litter”
Claim · model-written summary
Pig deep litter gave the highest nitrogen apparent nutrient recovery in aboveground plants.
Not reportedTaxonComparator
Verbatim
e0“Pig deep litter showed the highest N-ANR for the aboveground part of the plants.”
Claim · model-written summary
Pig slurry gave the highest apparent recovery of phosphorus, potassium, calcium and magnesium.
Not reportedTaxonComparator
Verbatim
e0“The ANRs for P, K, Ca, and Mg were also highest when pig slurry had been applied.”
Claim · model-written summary
Organic sources produced large marginal micronutrient offtake gains relative to mineral fertilizer.
- Treatment
- organic sourcese0
- Outcome
- micronutrientse0
- Direction
- large marginal offtake gainse0
- Comparator
- mineral fertilizatione0
Not reportedTaxon
Verbatim
e0“The ANR values for the micronutrients varied widely among the organic sources but indicated large marginal offtake gains compared to mineral fertilization.”
Claim · model-written summary
Animal manures increased plant nutrient uptake.
Not reportedTaxonComparator
Verbatim
e0“The N-based fertilization with animal manures increased the rate of nutrient uptake by plants”
Claim · model-written summary
Manure applications should be monitored regularly to avoid harmful nutrient accumulation.
- Outcome
- monitored regularlye0
Not reportedTaxon
Verbatim
e0“Manure applications must be monitored regularly to avoid the accumulation of nutrients that could impair the soil quality and become an environmental problem in the future.”
The same questions in other papers
fertilization · yield · Zea mays (maize)Positive and negative results
3,484 papers in the same direction as this paper · 338 in the opposite direction · 85 reporting no difference from an alternative
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