Crop rotation effects on soil carbon and physical fertility of two Australian soils

Soil Research ◽  
2000 ◽  
Vol 38 (1) ◽  
pp. 71 ◽  
Author(s):  
Nelly Blair ◽  
G. J. Crocker

The effect of using different crop rotations, including legumes and fallows, on soil structural stability, unsaturated hydraulic conductivity, and the concentration of different carbon fractions was examined in a long-term rotation trial established in 1966 on a Black Earth (Pellic Vertisol) and a Red Clay (Chromic Vertisol) soil. There was a large decrease in the concentration of soil carbon fractions following cropping and cultivation on both soils. The inclusion of some legume rotation crops resulted in an increase in labile carbon concentrations compared with continuous wheat or a long fallow treatment. Aggregate stability to wetting under both immersion and tension wetting was reduced as a result of cropping and cultivation for both soil types. However, there was an improvement in aggregate stability with immersion wetting, on the Red Clay soil, for the lucerne (Medicago sativa), clover (Trifolium subterraneum), and continuous wheat (Triticum aestivium) treatments compared with the long fallow. Similar results were found for the Black Earth soil; however, on this soil the medic (Medicago scutella) rotation also showed an improvement in soil structure. On the Red Clay soil there was a decrease in hydraulic conductivity (K) with cropping, at all tensions measured. K for the Black Earth soil was higher at 30 and 40 mm tension on the cropped soil than on the uncropped reference soil, but at 10 mm tension the reference soil had a higher K value than all rotations except the lucerne. There was a significant correlation between labile carbon and all determinations of aggregate stability for the Red Clay soil. Farmers should be encouraged to eliminate long fallowing and to adopt no-till techniques combined with the return of residues from either the primary crop or rotation crops which have a slower breakdown rate, as this management is likely to have a better potential for increasing soil carbon content and improving soil structure. The investigation of ways to better increase the quantity and quality of soil organic matter and hence soil chemical and physical fertility is necessary if long-term sustainable agriculture is to be possible.

2021 ◽  
Vol 13 (3) ◽  
pp. 1541
Author(s):  
Xiaolin Shen ◽  
Lili Wang ◽  
Qichen Yang ◽  
Weiming Xiu ◽  
Gang Li ◽  
...  

Our study aimed to provide a scientific basis for an appropriate tillage management of wheat-maize rotation system, which is beneficial to the sustainable development of agriculture in the fluvo-aquic soil areas in China. Four tillage treatments were investigated after maize harvest, including rotary tillage with straw returning (RT), deep ploughing with straw returning (DP), subsoiling with straw returning (SS), and no tillage with straw mulching (NT). We evaluated soil organic carbon (SOC), dissolved organic carbon (DOC), permanganate oxidizable carbon (POXC), microbial biomass carbon (MBC), and particulate organic carbon (POC) in bulk soil and soil aggregates with five particle sizes (>5 mm, 5–2 mm, 2–1 mm, 1–0.25 mm, and <0.25 mm) under different tillage managements. Results showed that compared with RT treatment, NT treatment not only increased soil aggregate stability, but also enhanced SOC, DOC, and POC contents, especially those in large size macroaggregates. DP treatment also showed positive effects on soil aggregate stability and labile carbon fractions (DOC and POXC). Consequently, we suggest that no tillage or deep ploughing, rather than rotary tillage, could be better tillage management considering carbon storage. Meanwhile, we implied that mass fractal dimension (Dm) and POXC could be effective indicators of soil quality, as affected by tillage managements.


2015 ◽  
Vol 63 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Karsten Schacht ◽  
Bernd Marschner

Abstract The use of treated wastewater (TWW) for agricultural irrigation becomes increasingly important in water stressed regions like the Middle East for substituting fresh water (FW) resources. Due to elevated salt concentrations and organic compounds in TWW this practice has potential adverse effects on soil quality, such as the reduction of hydraulic conductivity (HC) and soil aggregate stability (SAS). To assess the impact of TWW irrigation in comparison to FW irrigation on HC, in-situ infiltration measurements using mini disk infiltrometer were deployed in four different long-term experimental orchard test sites in Israel. Topsoil samples (0-10 cm) were collected for analyzing SAS and determination of selected soil chemical and physical characteristics. The mean HC values decreased at all TWW sites by 42.9% up to 50.8% compared to FW sites. The SAS was 11.3% to 32.4% lower at all TWW sites. Soil electrical conductivity (EC) and exchangeable sodium percentage (ESP) were generally higher at TWW sites. These results indicate the use of TWW for irrigation is a viable, but potentially deleterious option, as it influences soil physical and chemical properties.


Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 939
Author(s):  
Qiang Chen ◽  
Xingyi Zhang ◽  
Li Sun ◽  
Jianhua Ren ◽  
Yaru Yuan ◽  
...  

Tillage practices are critical for sustaining soil quality necessary for successful crop growth and productivity, but there are only few studies for strip tillage (ST) in the Mollisols region of Northeast China at present. A long-term (≥10-year) study was carried out to investigate the influence of within the tilled row (IR) and between rows (BR) in ST (10-year), conventional tillage (CT, 14-year) and no tillage (NT, 14-year) treatments on soil physicochemical properties. Soil samples were taken in May of 2019 at 0–5, 5–10, 10–20 and 20–30 cm depths and used to analyze bulk density (BD), soil aggregate distribution and stability, and soil organic carbon (SOC). Meanwhile, our study also explored the differences in seed emergence, soil moisture, and temperature during the seed emergence period, and yield of maize (Zea mays L.) among the different treatments. Similar soil properties were observed between ST-BR and NT, which showed they had a significantly greater BD, >0.25 mm water stable aggregate content (WR0.25) (especially in the amount of >2 mm and 1–2 mm size proportion), aggregate stability, and SOC than ST-IR and CT-IR at a depth of 0–20 cm. By improving soil conditions of seedbed, ST-IR and CT-IR increased soil temperature above NT by 1.64 °C and 1.80 °C, respectively, and ST-IR had a slight greater soil moisture than CT-IR in the top 10 cm layer during the seed emergence period. Late maize seed emergence was observed NT in than ST-IR and CT-IR and the average annual yields in ST were slightly greater than NT and CT, but the differences were not significant. Our results also showed that CT-BR had a poor soil structure and lower SOC than other treatments at 0–30 cm depth. We conclude from these long-term experimental results that ST could improve soil water-heat conditions to promote seed germination, maintain soil structure, and increase the maize yield and it should be applied in the Mollisols region of Northeast China.


Soil Research ◽  
1992 ◽  
Vol 30 (3) ◽  
pp. 265 ◽  
Author(s):  
HP Cresswell ◽  
DE Smiles ◽  
J Williams

We review the influence of soil structural change on the fundamental soil hydraulic properties (unsaturated hydraulic conductivity and the soil moisture characteristic) and utilize deterministic modelling to assess subsequent effects on the soil water balance. Soil structure is reflected in the 0 to -100 kPa matric potential section of the soil moisture characteristic with marked changes often occurring in light to medium textured soils' (sands, sandy-loam, loams and clay-loams). The effect of long-term tillage on soil structure may decrease hydraulic conductivity within this matric potential range. The 'SWIM' (Soil Water Infiltration and Movement) simulation model was used to illustrate the effects of long-term conventional tillage and direct drilling systems on the water balance. The effects of plough pans, surface crusts and decreasing surface detention were also investigated. Significant structural deterioration, as evidenced by substantially reduced hydraulic conductivity, is necessary before significant runoff is generated in the low intensity rainfall regime of the Southern Tablelands (6 min rainfall intensity <45 mm h-1). A 10 mm thick plough pan (at a depth of 100 mm) in the A-horizon of a long-term conventionally tilled soil required a saturated hydraulic conductivity (K,) of less than 2.5 mm h-1 before runoff exceeded 10% of incident rainfall in this rainfall regime. Similarly, a crust K, of less than 2.5 mm h-1 was necessary before runoff exceeded 10% of incident rainfall (provided that surface detention was 2 or more). As the crust K, approached the rainfall rate, small decreases in Ks resulted in large increases in runoff. An increase in surface detention of 1 to 3 mm resulted in a large reduction in runoff where crust K, was less than 2-5 mm h-1. Deterministic simulation models incorporating well established physical laws are effective tools in the study of soil structural effects on the field water regime. Their application, however, is constrained by insufficient knowledge of the fundamental hydraulic properties of Australian soils and how they are changing in response to our land management.


2020 ◽  
Author(s):  
Viktória Labancz ◽  
András Sebők ◽  
Imre Czinkota ◽  
Tamás Szegi ◽  
András Makó

&lt;p&gt;Today, due to climate change, soil degradation processes related to extreme water supply situations (flood, inland water or drought) are occurring more and more frequently. Soil structure is one of the most important soil characteristics influencing many transport of materials (transport, storage of heat, gas, water and nutrients).Furthermore, it defines and ultimately determines the significant physical, chemical and biological processes involved and also the most important factor in agricultural crop production. Permanent water cover has a significant effect on soil structure, but the dynamics of disaggregation and the role of the soil factors influencing it is not yet fully understood. Our basic research aim is to investigate the effect of permanent water cover on soil structure on representative Hungarian soil samples. In our experiment, we sought to find the answer to the question of how long-term water coverage causes changes and damage to the soil structure under laboratory conditions by artificial water cover. We measured aggregate stability with Mastersizer 3000 Hydro LV laser diffractometry device and some soil chemistry parameters with Agilent 4210 MP-AES at different water cover times (selected in the literature). Based on experiences the effect of persistent water cover from the soil structure side can be most noticeable in the changes of macro- and microaggregate stability, as well as in the change of certain chemical parameters (e.g. calcium and iron content), thus, the aim of our research was to investigate these characteristics also. After compiling our results in a database, we evaluated and deduced statistical data on the long-term degradation effects of water cover. We also made an attempt to describe its disaggregation dynamics for different Hungarian soil types. Based on the results, we have selected the most sensitive soils for permanent water cover, which are also expected to be sensitive to extreme water management related to climate change.&lt;/p&gt;


Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 465 ◽  
Author(s):  
T. G. Shepherd ◽  
S. Saggar ◽  
R. H. Newman ◽  
C. W. Ross ◽  
J. L. Dando

The effects of increasing cropping and soil compaction on aggregate stability and dry-sieved aggregate-size distribution, and their relationship to total organic C (TOC) and the major functional groups of soil organic carbon, were investigated on 5 soils of contrasting mineralogy. All soils except the allophanic soil showed a significant decline in aggregate stability under medium- to long-term cropping. Mica-rich, fine-textured mineral and humic soils showed the greatest increase in the mean weight diameter (MWD) of dry aggregates, while the oxide-rich soils, and particularly the allophanic soils, showed only a slight increase in the MWD after long-term cropping. On conversion back to pasture, the aggregate stability of the mica-rich soils increased and the MWD of the aggregate-size distribution decreased, with the humic soil showing the greatest recovery. Aggregate stability and dry aggregate-size distribution patterns show that soil resistance to structural degradation and soil resilience increased from fine-textured to coarse-textured to humic mica-rich soils to oxide-rich soils to allophanic soils. Coarse- and fine-textured mica-rich and oxide-rich soils under pasture contained medium amounts of TOC, hot-water soluble carbohydrate (WSC), and acid hydrolysable carbohydrate (AHC), all of which declined significantly under cropping. The rate of decline varied with soil type in the initial years of cropping, but was similar under medium- and long-term cropping. TOC was high in the humic mica-rich and allophanic soils, and levels did not decline appreciably under medium- and long-term cropping. 13C-nuclear magnetic resonance evidence also indicates that all major functional groups of soil organic carbon declined under cropping, with O-alkyl C and alkyl C showing the fastest and slowest rate of decline, respectively. On conversion back to pasture, both WSC and AHC returned to levels originally present under long-term pasture. TOC recovered to original pasture levels in the humic soil, but recovered only to 60–70% of original levels in the coarse- and fine-textured soils. Aggregate stability was strongly correlated to TOC, WSC, and AHC (P < 0.001), while aggregate-size distribution was moderately correlated to aggregate stability (P < 0.01) and weakly correlated to AHC (P < 0.05). Scanning electron microscopy indicated a loss of the binding agents around aggregates under cropping. The effect of the loss of these binding agents on soil structure was more pronounced in mica-rich soils than in oxide-rich and allophanic soils. The very high aggregate stabilities of the humic soil under pasture was attributed to the presence of a protective water-repellent lattice of long-chain polymethylene compounds around the soil aggregates.


2018 ◽  
Vol 98 (3) ◽  
pp. 421-435 ◽  
Author(s):  
J.J. Miller ◽  
B.W. Beasley ◽  
C.F. Drury ◽  
F.J. Larney ◽  
X. Hao ◽  
...  

Long-term application of feedlot manure to cropland may change the physical properties of soils. We measured selected soil (surface) physical properties of a Dark Brown Chernozemic clay loam where different amendments were annually applied for 15 (2013), 16 (2014), and 17 (2015) yr. The treatments were stockpiled (SM) or composted (CM) manure with either straw (ST) or wood-chip (WD) bedding applied at three rates (13, 39, and 77 Mg ha−1) and an unamended control. The effect of selected or all treatments on selected properties was determined in 2013–2015. These properties included field-saturated (Kfs) and near-saturated hydraulic conductivity or K(ψ), bulk density (BD), volumetric water content, soil temperature, soil thermal properties, and wet aggregate stability. The hypotheses that selected soil physical properties would improve more for treatments with greater total carbon in the amendments (SM > CM, WD > ST) was rejected. The exceptions were significantly (P ≤ 0.05) lower soil BD for SM than CM and WD than ST for certain dates, and lower soil thermal conductivity for WD than ST. Most soil physical properties generally had no response to 15–17 yr of annual applications of these feedlot amendments, but a few showed a positive response.


Soil Research ◽  
2007 ◽  
Vol 45 (3) ◽  
pp. 218 ◽  
Author(s):  
J. M. Kirkham ◽  
B. A. Rowe ◽  
R. B. Doyle

Changes in the soil structure and hydraulic conductivity of an Acidic Red Ferrosol were measured in a long-term (1968–2003) fertiliser experiment on pasture in north-western Tasmania, Australia. Studies were initiated following observations of both softer soil surface and cracking on plots that had received 15 t/ha of ground agricultural limestone. Liming decreased penetration resistance and increased hydraulic conductivity. These structural improvements were associated with increased mean dry aggregate size, a small increase in wet aggregate stability, higher exchangeable calcium levels, and increased plant growth, but a 9% decrease in total soil organic carbon in the surface 50 mm. This decrease in organic carbon was not associated with deterioration in soil structure, as may have been anticipated. This was probably because total organic C was still 82 g/kg on unlimed plots. Decreases in soil penetration resistance due to liming increased the likelihood of pugging from livestock but may improve ease of tillage. This research demonstrates that liming can improve the structure of a well-aggregated Ferrosol as well as its previously reported effects of increasing soil pH and yields of pasture and barley despite decreasing organic C.


1999 ◽  
Vol 39 (4) ◽  
pp. 445 ◽  
Author(s):  
R. D. Armstrong ◽  
B. J. Kuskopf ◽  
G. Millar ◽  
A. M. Whitbread ◽  
J. Standley

Incorporating legumes into the cropping system has been shown to significantly improve the nitrogen nutrition of cereal crops in Central Queensland. However, little is known about the effect of these legumes on the chemical and physical properties of soil. We examined changes in soil chemical (total nitrogen, organic carbon and pH) and physical (bulk density, cone penetrometer resistance and saturated hydraulic conductivity) properties following either continuous cropping (sorghum or mungbean) or pasture legumes (siratro, lucerne, lablab and desmanthus) over 4 years. Soil carbon was also fractionated using a KMnO4 oxidation procedure which classifies the soil carbon into either labile or non-labile pools. All pasture legumes except desmanthus increased soil total nitrogen in the topsoil (0–10 cm) after only 2 years compared with sorghum. Total nitrogen in the soil did not significantly change under mungbean. Soil organic carbon progressively increased under siratro, desmanthus and sorghum but remained unchanged under the other legumes. Before the experiment, the percentage of total soil carbon classified as labile (oxidised by 333 mmol KMnO4/L) ranged from 14 to 17%. The amount of labile carbon increased by 17% after 3 years of siratro, remained unchanged under desmanthus and sorghum, and decreased under the annual legumes and lucerne. Non-labile carbon remained either unchanged or increased under all legumes, whereas it tended to decrease after 3 consecutive sorghum crops. Soil pH was generally highest under sorghum and lowest under lablab. Soil after sorghum had higher bulk density and penetrometer resistance compared with the effect of legumes but these differences were comparatively small. Saturated hydraulic conductivity of the soil was much higher on the soil surface than at 10 cm. On the surface, soil hydraulic conductivity (saturated) values were generally lower following siratro and higher after sorghum than the other species. At 10 cm depth, soil hydraulic conductivity (saturated) was generally lower in sorghum and, to a lesser extent, in mungbean plots reflecting the significantly lower density of macropores under these crops. It was concluded that although all legumes generally enhanced the chemical and physical properties of the cracking clay, perennial legumes such as siratro would have a greater beneficial effect in the longer term than annual legumes.


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