scholarly journals Multi-cooperation of soil biota in the plough layer is the key for conservation tillage to improve N availability and crop yield

2020 ◽  
Author(s):  
Shixiu Zhang ◽  
Liang Chang ◽  
Neil B. McLaughlin ◽  
Shuyan Cui ◽  
Haitao Wu ◽  
...  
Keyword(s):  
N Mineralization ◽  
Conservation Tillage ◽  
Soil Biota ◽  
Trophic Groups ◽  
Mineral N ◽  
Soybean Yield ◽  
Predator Prey ◽  
Soil N Mineralization ◽  
Plough Layer ◽  
Energy Pathways

Abstract. Conservation tillage facilitates constructing a more complex and heterogeneous distribution of soil organisms in the plough layer relative to conventional tillage (CT), which results in an improvement in crop yield and nitrogen (N) uptake. However, knowledge of how soil biota interact to couple mineralization of N and promote plant growth is still limited. The contribution of soil biota (trophic groups and energy pathways) to soil N mineralization and the relationship between energy pathways and grain yield during soybean (Glycine max Merr.) growing season were investigated at 0–5 and 5–15 cm depths under a long-term tillage trial. The trial was initiated in 2001 on a Black soil in Northeastern China and included no tillage (NT), ridge tillage (RT) and CT. A higher contribution of most trophic groups to soil N mineralization throughout the whole plough layer was observed in RT and NT than in CT, and these differences were more pronounced for higher trophic groups than for lower ones. Furthermore, the responses of trophic groups to tillage practices were also transferred into the energy pathways. Bacterial and predator-prey pathways released more mineral N in RT and NT than in CT. Multiple regression models revealed that soybean yield was significantly related to the mineralized N in RT and NT through root, fungal and prey-predator pathways in 0–5 cm and bacterial pathway in 5–15 cm. Additionally, the relative contribution of the mineralized N by different pathways to soybean yield was different in 0–5 cm and decreased in the order of root pathway (0.487) > fungal pathway (0.389) > predator-prey pathway (0.318). Although soil trophic groups coupled with N mineralization and soybean yield varied with depth in RT and NT soils, a stable supply of mineral N from soil to plant could be maintained in the plough layer by the cooperation of predator-prey pathway horizontally with bacterial and plant pathways and vertically with fungal and bacterial pathways. This favorable effect of multi-cooperation of soil biota on coupling N mineralization and plant growth in the plough layer is a cornerstone of conservation tillage benefits in temperate areas of the world.

scholarly journals Soil mineral N dynamics beneath mixtures of leaves from legume and fruit trees in Central Amazonian multi-strata agroforests

2007 ◽  
Vol 37 (3) ◽  
pp. 313-320 ◽  
Author(s):  
Carol Melanie Schwendener ◽  
Johannes Lehmann ◽  
Marco Rondon ◽  
Elisa Wandelli ◽  
Erick Fernandes
Keyword(s):  
N Mineralization ◽  
Dominant Factor ◽  
Soil N ◽  
Soil Mineral N ◽  
Residue Quality ◽  
Soil Mineral ◽  
Mineral N ◽  
N Dynamics ◽  
Soil N Mineralization ◽  
N Release

Long term applications of leguminous green mulch could increase mineralizable nitrogen (N) beneath cupuaçu trees produced on the infertile acidic Ultisols and Oxisols of the Amazon Basin. However, low quality standing cupuaçu litter could interfere with green mulch N release and soil N mineralization. This study compared mineral N, total N, and microbial biomass N beneath cupuaçu trees grown in two different agroforestry systems, north of Manaus, Brazil, following seven years of different green mulch application rates. To test for net interactions between green mulch and cupuaçu litter, dried gliricidia and inga leaves were mixed with senescent cupuaçu leaves, surface applied to an Oxisol soil, and incubated in a greenhouse for 162 days. Leaf decomposition, N release and soil N mineralization were periodically measured in the mixed species litter treatments and compared to single species applications. The effect of legume biomass and cupuaçu litter on soil mineral N was additive implying that recommendations for green mulch applications to cupuaçu trees can be based on N dynamics of individual green mulch species. Results demonstrated that residue quality, not quantity, was the dominant factor affecting the rate of N release from leaves and soil N mineralization in a controlled environment. In the field, complex N cycling and other factors, including soil fauna, roots, and microclimatic effects, had a stronger influence on available soil N than residue quality.

Factors controlling N mineralization, nitrification, and nitrogen losses in an Oxisol amended with sewage sludge

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 519 ◽  
Author(s):  
J. Sierra ◽  
S. Fontaine ◽  
L. Desfontaines
Keyword(s):  
Sewage Sludge ◽  
Field Experiment ◽  
Water Content ◽  
N Mineralization ◽  
Initial Period ◽  
Factorial Experiment ◽  
Net N Mineralization ◽  
N Losses ◽  
Mineral N ◽  
The Difference

Laboratory incubations and a field experiment were carried out to determine the factors controlling N mineralization and nitrification, and to estimate the N losses (leaching and volatilization) in a sewage-sludge-amended Oxisol. Aerobically digested sludge was applied at a rate equivalent to 625 kg N/ha. The incubations were conducted as a factorial experiment of temperature (20˚C, 30˚C, and 40˚C) soil water (–30 kPa and –1500 kPa) sludge type [fresh (FS) water content 6230 g/kg; dry (DS) water content 50 g/kg]. The amount of nitrifiers was determined at the beginning and at the end of the experiment. The incubation lasted 24 weeks. The field study was conducted using bare microplots (4 m) and consisted of a factorial experiment of sludge type (FS and DS) sludge placement (subsurface, I+; surface, I–). Ammonia volatilization and the profile (0–0.90 m) of mineral N concentration were measured during 6 and 29 weeks after sludge application, respectively. After 24 weeks of incubation at 40˚C and –30 kPa, net N mineralization represented 52% (FS) and 71% (DS) of the applied N. The difference between sludges was due to an initial period of N immobilization in FS. Nitrification was more sensitive than N mineralization to changes in water potential and it was fully inhibited at –1500 kPa. The introduction of a large amount of nitrifiers with FS did not modify the rate of nitrification, which was principally limited by soil acidity (pH 4.9). Although N mineralization was greatest at 30˚C, nitrification increased continuously with temperature. Nitrogen mineralization from DS was well described by the double-exponential equation. For FS, the equation was modified to take into account an immobilization-remineralization period. Sludge placement significantly affected the soil NO-3/NH+4 ratio in the field: 16 for I+ and 1.5 for I–, after 11 weeks. In the I– treatment, nitrification of the released NH+4 was limited by soil moisture because of the dry soil mulch formed a few hours after rain. At the end of the field experiment, the estimated losses of N by leaching were 432 kg N/ha for I+ and 356 kg N/ha for I–. Volatilization was not detectable in the I+ microplots and it represented only 0.5% of the applied N in the I– microplots. The results showed that placement of sludge may be a valuable tool to decrease NO-3 leaching by placing the sludge under unfavourable conditions for nitrification.

scholarly journals Plant effects on soil N mineralization are mediated by the composition of multiple soil organic fractions

2010 ◽  
Vol 26 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Dario A. Fornara ◽  
Richard Bardgett ◽  
Sibylle Steinbeiss ◽  
Donald R. Zak ◽  
Gerd Gleixner ◽  
...  
Keyword(s):  
N Mineralization ◽  
Soil N ◽  
Soil N Mineralization ◽  
Plant Effects ◽  
Organic Fractions

scholarly journals Mid-Term Effects of Forest Thinning on N Mineralization in a Semi-Arid Aleppo Pine Forest

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1470
Author(s):  
Inmaculada Bautista ◽  
Luis Lado-Monserrat ◽  
Cristina Lull ◽  
Antonio Lidón
Keyword(s):  
N Mineralization ◽  
Nutrient Dynamics ◽  
Pinus Halepensis ◽  
Block Design ◽  
Plant Cover ◽  
Basal Area ◽  
Net N Mineralization ◽  
Mineral N ◽  
Silvicultural Treatments ◽  
Randomized Block Design

In order to assess the sustainability of silvicultural treatments in semiarid forests, it is necessary to know how they affect the nutrient dynamics in the forest. The objective of this paper is to study the effects of silvicultural treatments on the net N mineralization and the available mineral N content in the soil after 13 years following forest clearings. The treatments were carried out following a randomized block design, with four treatments and two blocks. The distance between the two blocks was less than 3 km; they were located in Chelva (CH) and Tuéjar (TU) in Valencia, Spain. Within each block, four experimental clearing treatments were carried out in 1998: T0 control; and T60, T75 and T100 where 60%, 75% and 100 of basal area was eliminated, respectively. Nitrogen dynamics were measured using the resin tube technique, with disturbed samples due to the high stoniness of the plots. Thirteen years after the experimental clearings, T100, T75 and T60 treatments showed a twofold increase in the net mineralization and nitrification rates with respect to T0 in both blocks (TU and CH). Within the plots, the highest mineralization was found in sites with no plant cover followed by those covered by undergrowth. These results can be explained in terms of the different litterfall qualities, which in turn are the result of the proportion of material originating from Pinus halepensis Mill. vs. more decomposable undergrowth residues.

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