Dynamics of microbial residues in highland agroecosystems as affected by cropping systems and fertilization in a 31‐year‐long experiment

Author(s):  
Fuyuan Su ◽  
Xu Chen ◽  
Liqiong Zhang ◽  
Mingde Hao ◽  
Xiaorong Wei
2021 ◽  
Author(s):  
Kirsten Hofmockel ◽  
Sheryl Bell ◽  
Chris Kasanke

<p>Microbial derivatives and necromass are dominant sources of soil organic matter (SOM), yet the specific microbiological and geochemical reactions leading to the persistence of microbial compounds in SOM remains to be discovered. Identification of the microbial taxa and classes of microbial-derived compounds that are selectively preserved may enhance our ability to manage SOM, particularly in agroecosystems. We examined how perennial and annual biofuel cropping systems influence the production and selective preservation of microbial residues. Our experiment was replicated on a sandy and a silty loam to test the relative importance of microbial (biotic) and mineral (abiotic) filters on necromass accumulation and persistence. Using a <sup>13</sup>C-labeling incubation experiment, we tested the effects of cropping system and soil texture on the production and persistence of microbial-derived residues. Soils were collected from sandy loams at the Kellogg Biological Station (MI, USA) and silty loams at the Arlington Agricultural Research Station (WI, USA). These soils were amended with <sup>13</sup>C-labeled glucose, which was rapidly incorporated into microbial biomass. After 2 months, ~50% of the added <sup>13</sup>C remained in the bulk soil. Approximately 30% of the <sup>13</sup>C remaining in the bulk soil was recovered in the lipid, protein, and metabolite pools. Lipids contained the most <sup>13</sup>C (16%) and the contribution was similar in both soils. Both soils had similar protein pools, but protein from the sandy loam was significantly more enriched than protein from the silty loam. The pool of metabolites was small, but highly enriched, suggesting substantial recycling over the 2-month incubation. The majority (40%) of the whole soil <sup>13</sup>C persisted in the SOM even after repeat extractions. The remaining ~30% of the whole soil <sup>13</sup>C was recovered in a complex of remaining unknown debris that separates from the soil at the solvent interphase with the protein but could not be solubilized. We provide novel evidence of the carbon pools that contribute to persistent microbial residues in soil. Our results suggest that metabolites may be more important than was previously recognized. Ongoing work is identifying the labeled metabolites and characterizing the chemistry of the highly enriched protein residue fraction.</p>


The present study was carried out in three districts viz; Rewari, Sirsa and Hisar of Haryana state. A survey of 60 sampled farms was conducted to extract information pertaining to various expenses incurred in cultivation of castor and output attained as well as to ascertain the perception of farmers for various problems encountered in production and marketing of castor seed. The descriptive analysis was employed to draw valid inferences from the study. The results revealed that net profit accrued from cultivation of castor seed was ₹ 46331 ha -1 in the study area. The value of B: C ratio of castor cultivation was more than one and also higher as compared to prevalent cropping systems indicated that cultivation of castor seed is economical viable entity. However, production constraints like retention of F2 seed in the field over year, grain scattering, shortage of irrigation water, frost effect on crop yield and marketing constraints like absence of MSP, higher transportation cost sale of castor seed in distant markets, frequent fluctuation in market price, non-availability of processing units were observed.


2019 ◽  
pp. 61-67

Recognition of high yielding and nitrogen (N) fixing groundnut genotypes and desegregating them in the cereal-based cropping systems common in savannah regions will enhance food security and reduce the need for high N fertilizers hence, minimize the high cost and associated environmental consequences. Field trials were conducted during the 2015 growing season at the Research Farms of Bayero University Kano (BUK) and Institute for Agricultural Research (IAR), Ahmadu Bello University, Samaru-Zaria to assess the yield potential and Biolog- ical N fixation in 15 groundnut genotypes (ICG 4729, ICGV-IS 07823, ICGV-IS 07893, ICGV-IS 07908, ICGV- SM 07539, ICGV- SM 07599, ICGV-IS 09926, ICGV-IS 09932, ICGV-IS 09992, ICGV-IS 09994, SAMNUT-21, SAMNUT-22, SAMNUT-25, KAMPALA and KWANKWAS). The groundnut genotypes and reference Maize crop (SAMMAZ 29) were planted in a randomized complete block design in three replications. N difference method was used to estimate the amount of N fixed. The parameters determined were the number of nodules, nod- ule dry weight, shoot and root dry weights, pod, and haulm yield as well as N fixation. The nodule dry weight, BNF, haulm, and pod yield were statistically significant (P<0.01) concerning genotype and location. Similarly, their interac- tion effect was also highly significant. ICGV-IS 09926 recorded the highest nod- ule dry weight of 2.07mg /plant across the locations while ICGV-IS 09932 had the highest BNF value of 140.27Kg/ha. Additionally, KAMPALA had the high- est haulm yield, while ICGV-IS 07893 had the highest pod yield across the loca- tions with a significant interaction effect. The result shows that ICGV-IS 07893 and ICGV-IS 09932, as well as ICGV-IS 09994 and SAMNUT – 22, were the best genotypes concerning BNF, haulm and pod yield in the Northern Guinea and Sudan Savannahs of Nigeria respectively with the potential for a corresponding beneficial effect.


2015 ◽  
Vol 41 (9) ◽  
pp. 1393 ◽  
Author(s):  
Bao-Yuan ZHOU ◽  
Zhi-Min WANG ◽  
Yang YUE ◽  
Wei MA ◽  
Ming ZHAO

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

jpa ◽  
1993 ◽  
Vol 6 (2) ◽  
pp. 290-296 ◽  
Author(s):  
John C. Foltz ◽  
John G. Lee ◽  
Marshall A. Martin

2003 ◽  
Vol 67 (2) ◽  
pp. 637 ◽  
Author(s):  
Achmad Rachman ◽  
S. H. Anderson ◽  
C. J. Gantzer ◽  
A. L. Thompson

1993 ◽  
Vol 28 (3-5) ◽  
pp. 691-700 ◽  
Author(s):  
J. P. Craig ◽  
R. R. Weil

In December, 1987, the states in the Chesapeake Bay region, along with the federal government, signed an agreement which called for a 40% reduction in nitrogen and phosphorus loadings to the Bay by the year 2000. To accomplish this goal, major reductions in nutrient loadings associated with agricultural management practices were deemed necessary. The objective of this study was to determine if reducing fertilizer inputs to the NT system would result in a reduction in nitrogen contamination of groundwater. In this study, groundwater, soil, and percolate samples were collected from two cropping systems. The first system was a conventional no-till (NT) grain production system with a two-year rotation of corn/winter wheat/double crop soybean. The second system, denoted low-input sustainable agriculture (LISA), produced the same crops using a winter legume and relay-cropped soybeans into standing wheat to reduce nitrogen and herbicide inputs. Nitrate-nitrogen concentrations in groundwater were significantly lower under the LISA system. Over 80% of the NT groundwater samples had NO3-N concentrations greater than 10 mgl-1, compared to only 4% for the LISA cropping system. Significantly lower soil mineral N to a depth of 180 cm was also observed. The NT soil had nearly twice as much mineral N present in the 90-180 cm portion than the LISA cropping system.


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