Crop Production and Soil Organic Matter in Long-Term Crop Rotations in the Semi-Arid Northern Great Plains of Canada

Author(s):  
C.A. Campbell ◽  
R.P. Zentner
1995 ◽  
Vol 35 (2) ◽  
pp. 233 ◽  
Author(s):  
AL Cogle ◽  
J Littlemore ◽  
DH Heiner

Soil organic matter changes due to cropping in the semi-arid tropics were studied in an area with cropping potential. Soil organic carbon and total nitrogen (N) decreased after clearing and tillage, but decline was less where pasture-crop rotations were used. Crop N removal was high and exceeded the recommended fertiliser N rate. These results suggest that if cropping expansion occurs, careful management the is necessary for long-term productivity and land resource protection.


2020 ◽  
Author(s):  
Kurt-Christian Kersebaum ◽  
Susanne Schulz ◽  
Evelyn Wallor

<p>Climate change impact on crop production depends on the cultivated crop and its position within crop rotations and on site conditions, e.g. soils and hydrology, buffering adverse weather situations. We present a regional study across the federal state of Brandenburg/Germany based on gridded climate data and a digital soil map using the HERMES-to-Go model. The aim was to investigate defined crop rotations and common agricultural practices under current and future climate conditions regarding productivity and environmental effects. Two contrasting GCMs (HAD and MPI) were used to generate climate input for modelling for the RCPs 2.6 and 8.5.</p><p>5 different types of crop production were simulated by defining crop rotations over 4-5 years for soil quality rating groups. While one rotation is comprised by the most common crops, another rotation modifies the first one by introducing a legume followed by a more demanding crop. The third rotation intends to produce higher value crops, e.g. potatoes than the first one, while the fourth rotation has its focus on fodder grass and cereal production. Building on this the fifth rotation replaces the fodder grass by alfalfa. All rotations are simulated in shifted phases to ensure that each crop is simulated for each year.</p><p>Sowing, harvest and nitrogen fertilization were derived by algorithms based on soil and climate information to allow self-adaptation to changing climate conditions. The crop rotations are simulated under rainfed and irrigated conditions and with and without the implementation of cover crops to prevent winter fallow.</p><p>We used the digital soil map 1:300.000 for Brandenburg with 99 soil map units. Within the soil map unit, up to three dominant soil types were considered to achieve at least 65% coverage. 276 soil types are defined by their soil profiles including soil organic matter content and texture down to 2 meters. Groundwater levels are estimated using the depth of reduction horizons as constant values over the year, to consider capillary rise depending on soil texture and distance between the root zone and the groundwater table.</p><p>In total each climate scenario contains about 148.000 simulations of 30 years. Beside crop yields we analyse the outputs for trends in soil organic matter, groundwater recharge, nitrogen leaching and the effect on water and nitrogen management using algorithms for automatic management.</p><p>Results indicate that spring crops were more negatively affected by climate change than winter crops especially on soils with low water holding capacity. However, few areas with more loamy soils and potential contribution of capillary rise from a shallow groundwater even benefited from climate change. Irrigation in most cases improved crop yield especially for spring crops. However, further analysis is required to assess if irrigation gains an economic benefit for all crop rotations. Nitrogen leaching can be reduced by implementing winter cover crops. Soil organic matter is assessed to decline for most sites and rotations. Only the rotations with multiyear grass or alfalfa can keep the level, but not on all sites.</p>


Soil Research ◽  
2015 ◽  
Vol 53 (4) ◽  
pp. 377 ◽  
Author(s):  
D. Curtin ◽  
P. M. Fraser ◽  
M. H. Beare

Cultivation of grassland is known to lead to the depletion of soil organic matter (SOM), but the effect on the size and composition of the exchangeable cation suite has not been documented. We measured cation exchange capacity (CEC) and exchangeable cations (calcium, Ca; magnesium, Mg; potassium, K; sodium, Na), as well as soil carbon (C) and nitrogen (N) (0–7.5, 7.5–15, and 15–25 cm), 8 years after conversion of long-term ryegrass–white clover pasture (grazed by sheep) to annual crop production. The trial was near Lincoln, Canterbury, New Zealand. The trial included three tillage treatments: crops established using intensive cultivation (mouldboard ploughing), minimum tillage (shallow cultivation, ~10 cm), or no-tillage. The 8-year rotation was barley, wheat, pea, barley, pea, barley, barley, barley. A sheep-grazed pasture was maintained as an experimental control. The experiment also included a permanent fallow treatment (maintained plant-free using herbicides; not cultivated). After 8 years under arable cropping, soil C stocks (0–25 cm) were 10 t ha–1 less, on average, than under pasture. The vertical distribution of soil organic matter (SOM) was affected by tillage type, but the total amount of organic matter in the top 25 cm did not differ (P > 0.05) among the tillage treatments. Under permanent fallow (C loss of 13 t ha–1 relative to pasture), total exchangeable cation (Ca + Mg + K +Na) equivalents declined by 47 kmolc ha–1, a 20% decrease compared with pasture. Loss of exchange capacity resulted in the selective release of cations with lower affinity for SOM (K, Na, Mg). Smaller losses of exchangeable cations were recorded under the arable cropping rotation (average 31 kmolc ha–1), with no differences among tillage treatments. Effective CEC (at field pH) decreased under permanent fallow and cultivated treatments because of: (1) depletion of SOM (direct effect); and (2) soil acidification, which eliminated some of the remaining exchange sites (indirect effect). Acidification in the permanent fallow can be attributed to the N mineralisation process, whereas in the cropped systems, excess cation removal in harvested straw and grain accounted for about half of the measured acidification. There was evidence that the organic matter lost under arable cropping and fallow had lower CEC than SOM as a whole.


2013 ◽  
Vol 134 ◽  
pp. 133-141 ◽  
Author(s):  
Joy L. Barsotti ◽  
Upendra M. Sainju ◽  
Andrew W. Lenssen ◽  
Cliff Montagne ◽  
Patrick G. Hatfield

2007 ◽  
Vol 99 (4) ◽  
pp. 904-911 ◽  
Author(s):  
D. L. Tanaka ◽  
J. M. Krupinsky ◽  
S. D. Merrill ◽  
M. A. Liebig ◽  
J. D. Hanson

2019 ◽  
Vol 135 ◽  
pp. 396-406 ◽  
Author(s):  
Bryony E.A. Dignam ◽  
Maureen O'Callaghan ◽  
Leo M. Condron ◽  
Jos M. Raaijmakers ◽  
George A. Kowalchuk ◽  
...  

Author(s):  
Haiming Tang ◽  
Chao Li ◽  
Lihong Shi ◽  
Li Wen ◽  
Kaikai Cheng ◽  
...  

Abstract Soil organic matter (SOM) and its fractions play an important role in maintaining or improving soil quality and soil fertility. Therefore, the effects of a 34-year long-term fertilizer regime on six functional SOM fractions under a double-cropping rice paddy field of southern China were studied in the current paper. The field experiment included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM) and without fertilizer input as control (CK). The results showed that coarse unprotected particulate organic matter (cPOM), biochemically, physically–biochemically and chemically protected silt-sized fractions (NH-dSilt, NH-μSilt and H-dSilt) were the main carbon (C) storage fractions under long-term fertilization conditions, accounting for 16.7–26.5, 31.1–35.6, 16.2–17.3 and 7.5–8.2% of the total soil organic carbon (SOC) content in paddy soil, respectively. Compared with control, OM treatment increased the SOC content in the cPOM, fine unprotected POM fraction, pure physically protected fraction and physico-chemically protected fractions by 58.9, 106.7, 117.6 and 28.3%, respectively. The largest proportion of SOC to total SOC in the different fractions was biochemically protected, followed by chemically and unprotected, and physically protected were the smallest. These results suggested that a physical protection mechanism plays an important role in stabilizing C of paddy soil. In summary, the results showed that higher functional SOM fractions and physical protection mechanism play an important role in SOM cycling in terms of C sequestration under the double-cropping rice paddy field.


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