Weed Community Composition after 26 Years of Fertilization of Late Rice

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 256-260 ◽  
Author(s):  
Jun Nie ◽  
Li C. Yin ◽  
Yu L. Liao ◽  
Sheng X. Zheng ◽  
Jian Xie

To assess the influence of long-term fertilization on weed communities of early and late rice crops, the weed species composition was investigated in experimental plots initiated in 1981 at the Key Field Experimental Monitoring Station of the Reddish Paddy Soil Eco-Environment in Wangcheng, China. The treatments were (1) a control (CK), no fertilizer; (2) N–P, no K; (3) N–K, no P; (4) P–K, no N; (5) N–P–K; (6) N–P–K + Ca, N, P, and K plus lime; (7) N–P + S, N and P plus additional rice straw return; (8) N–P–K + S, N, P, and K plus additional rice straw; (9) N–K + M, N and K plus swine manure. The results indicated that weed flora composition and density were influenced by the different fertilization treatments. Multivariate analyses indicated that changes in the weed community composition were primarily due to soil-available N, followed by light intensity on the field surface, and soil-available P. More weed species and total weed density were observed in the control and P–K plots than in plots in which N, P, and K were applied together. Omission of N application had a greater effect on the weed community than the omission of P or K applications. Nutrients derived from synthetic fertilizers and organic manure or the additional application of lime had no obvious effect on the weed community of late rice crops.

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 261-270 ◽  
Author(s):  
Lynn M. Sosnoskie ◽  
Catherine P. Herms ◽  
John Cardina ◽  
Theodore M. Webster

The compositions of the germinable weed seedbank and aboveground weed communities in a long-term tillage and rotation study were characterized 4, 5, and 6 yr (2002 to 2004) after the adoption of glyphosate-tolerant corn and soybean. Averaged across rotation, mean germinable weed seed density and diversity were greatest in the no-tillage treatment as compared to the minimum- and conventional-tillage treatments. Averaged over tillage, density and diversity were greater in the corn–oat–hay (ryegrass + alfalfa) system as compared to the continuous corn and corn–soybean rotations. Similar trends in density and diversity were observed for the aboveground weed communities. Differences in community composition among treatments were quantified with the use of a multiresponse permutation procedure. Results indicated that the weed seedbank community in a corn–oat–hay rotational system differed from the communities associated with the continuous corn and corn–soybean rotational systems. Weed seedbank communities developing under a no-tillage operation differed from those in minimum- and conventional-tillage scenarios. Compositional differences among the aboveground weed communities were less pronounced in response to tillage and rotation. Indicator species analyses indicated that the number of significant indicator weed species was generally higher for no tillage than minimum or conventional tillage for both the seedbank and the aboveground weed communities. The number of significant indicator species for the seedbank and weed communities was generally greater in the three-crop rotation as compared to the continuous corn and corn–soybean rotations. The trends observed in density, diversity, and community composition after the adoption of glyphosate-tolerant corn and soybeans, and a glyphosate-dominated weed management program, were also observed when soil-applied herbicides were included in the study. We suggest that the switch to a POST-glyphosate protocol did not significantly alter weed communities in the short term in this study.


Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 714-721 ◽  
Author(s):  
Amy E. Sweeney ◽  
Karen A. Renner ◽  
Carrie Laboski ◽  
Adam Davis

The timing of nitrogen (N) fertilizer application may influence germination, emergence, and competitiveness of weeds. Research was conducted to determine the influence of total inorganic soil N (Nit) on the germination, emergence, and growth of five weed species. In a greenhouse experiment, seed of five weed species were exposed to four levels of N, and seed germination was measured. In the field, urea ammonium nitrate (UAN 28%) was applied at multiple rates at three spring timings, and Nit, weed emergence, and growth were measured for 21 to 35 d after application (DAA). Germination of the four dicotyledonous and single grass species was not stimulated by 450 ppmw of N compared with the untreated control. In the field, Nitof 112 or 168 kg N ha−1, measured at 7 and 21 DAA, was always greater than Nitin the untreated control. The duration of the available N pulse in the upper 8 cm of soil was dependent on N application rate and timing. At 8 to 16 cm of soil depth, Nitwas greater when 168 kg N ha−1was applied compared with no N at 21 and 35 DAA in 2004. Emergence of common lambsquarters increased as N application rate increased for each application date in 2003, but not in 2004. Emergence of ladysthumb increased with N application rate for the April 15, 2003, date; emergence of giant foxtail increased with N application rate for the April 6, 2004, date. Weed biomass was always greater when 168 kg N ha−1was applied compared with no N, and at four of six N application dates, when 112 kg N ha−1was applied. This research shows that spring N fertilizer applications increase Nitand weed growth, but the influence of N on weed emergence is dependent on the weed species, seed source, and environmental conditions.


Weed Science ◽  
2018 ◽  
Vol 66 (5) ◽  
pp. 651-661
Author(s):  
Nathaniel M. Drewitz ◽  
David E. Stoltenberg

AbstractPrevious research has shown that strip-tillage (ST) systems conserve soil, reduce production costs, and save time for growers compared with intensive-tillage systems. In contrast to these well-documented benefits, we have limited information on weed community dynamics and management risks in ST corn (Zea maysL.) production systems in the northern Corn Belt. Therefore, we conducted research in 2015 and 2016 to characterize weed community composition, emergence patterns, and aboveground productivity in an ST corn/no-tillage (NT) soybean [Glycine max(L.) Merr.] rotation that was established in 2007 compared with a long-term intensive-tillage chisel-plow (CP) continuous-corn system. Fifteen or more weed species were identified in nontreated quadrats in each cropping system in each year. Common lambsquarters (Chenopodium albumL.) was the most abundant weed species across systems and years.Chenopodium albumdensities were similar between CP and ST corn phases and were approximately 2-fold greater compared with the NT soybean phase. Other abundant weed species occurred at much lower densities thanC. album. In each year, cumulative emergence of nontreated weed communities was described best by a logistic function in each cropping system. Maximum weed community emergence was greater in CP corn than ST corn phases in 2015, but did not differ in 2016. In the ST corn phase, most (about 75%) weed community emergence occurred in the in-row (tilled) zone compared with the between-row (nondisturbed) zone. Total late-season weed shoot biomass did not differ between nontreated CP and ST corn phases in either year, withC. albumaccounting for >85% of total weed biomass in these phases. These results suggest that weed community composition, total emergence, and productivity were similar between CP and ST corn phases after 10 yr. Our findings, coupled with previous research that showed favorable agronomic performance and greater soil conservation associated with the long-term ST corn/NT soybean system, suggest that production risks are no greater than a CP corn system, while processes that underpin ecosystem services are enhanced. These results provide strong evidence to support grower adoption of ST practices as an alternative to intensive tillage.


2013 ◽  
Vol 14 (4) ◽  
pp. 497
Author(s):  
Desimir Knežević ◽  
Dimitrije Marković ◽  
Sretenka Marković ◽  
Danijela Kondić

In this study we tested yield and weediness in wheat cultivars Lazarica and Julija Mono grown under different regime of mineral nutrition. This investigation was conducted at the long term experiment on control variant (without fertilizers), second variant with nitrogen application (two sub variants with different rate of N) 2N1 (80 kg N ha-1) and 2N2 (120 kg N ha-1), third variant with NP fertilizer with two different rate of N application: 3N1 (80 kg N ha-1 + 100kg P ha-1) and 3N2 (120 kg N ha-1 + 100kg P ha-1) and fourth variant 4N1 (80 kg N ha-1 + 60kg P ha-1) and 4N2 (120 kg N ha-1 + 60kg P ha-1). Weediness varies in dependence of rate and variant of fertilization. The weed species Consolida regalis Gray, Convolvulus arvensis L., Polygonum aviculare L., Cirsium arvense L., Agropyrum repens L., Polygonum convolvulus L. was dominant on fertilized plots. The analyzed variability of grain yield depends of applied fertilizer variants. The lowest grain yield was found on control variant in both wheat cultivar Lazatica (1880kg ha-1), Julija Mono (1740kg ha-1) while the highest grain yield on variant 3N2 (120 kg N ha-1 + 100kg P ha-1) Lazarica (3724kg ha-1 Julija Mono (4990kg ha-1) and low weediness.


Pedosphere ◽  
2007 ◽  
Vol 17 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Jun NIE ◽  
Jian-Min ZHOU ◽  
Huo-Yan WANG ◽  
Xiao-Qin CHEN ◽  
Chang-Wen DU

2014 ◽  
Vol 63 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Éva Lehoczky ◽  
M. Kamuti ◽  
N. Mazsu ◽  
J. Tamás ◽  
D. Sáringer-Kenyeres ◽  
...  

Plant nutrition is one of the most important intensification factors of crop production. The utilization of nutrients, however, may be modified by a number of production factors, including weed presence. Thus, the knowledge of occurring weed species, their abundance, nutrient and water uptake is extremely important to establish an appropriate basis for the evaluation of their risks or negative effects on crops. That is why investigations were carried out in a long-term fertilization experiment on the influence of different nutrient supplies (Ø, PK, NK, NPK) on weed flora in maize field.The weed surveys recorded similar diversity on the experimental area: the species of A. artemisiifolia, S. halepense and D. stramonium were dominant, but C. album and C. hybridum were also common. These species and H. annuus were the most abundant weeds.Based on the totalized and average data of all treatments, density followed the same tendency in the experimental years. It was the highest in the PK treated and untreated plots, and significantly exceeded the values of NK fertilized areas. Presumably the better N availability promoted the development of nitrophilic weeds, while the mortality of other small species increased.Winter wheat and maize forecrops had no visible influence on the diversity and the intensity of weediness. On the contrary, there were consistent differences in the density of certain weed species in accordance to the applied nutrients. A. artemisiifolia was present in the largest number in the untreated control and PK fertilized plots. The density of S. halepense and H. annuus was also significantly higher in the control areas. The number of their individuals was smaller in those plots where N containing fertilizers were used. Contrary to them, the density of D. stramonium, C. album and C. hybridum was the highest in the NPK treatments.


Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 561
Author(s):  
Enze Wang ◽  
Xiaolong Lin ◽  
Lei Tian ◽  
Xinguang Wang ◽  
Li Ji ◽  
...  

Rice straw is a byproduct of agricultural production and an important agricultural resource. However, rice straw has not yet been effectively used, and incorrect treatment methods (such as burning in the field) can cause serious damage to the environment. Studies have shown that straw returning is beneficial to soil, but there have been few studies focused on the effect of the amount of short-term straw returned on the soil microbial community. This study evaluates 0%, 50%, 75%, and 100% rice straw returned to the field on whether returning different amounts of straw in the short term would affect the diversity and composition of the soil microbial community and the correlation between bacteria and fungi. The results show that the amount of straw returned to the field is the main factor that triggers the changes in the abundance and composition of the microbial community in the paddy soil. A small amount of added straw (≤ 50% straw added) mainly affects the composition of the bacterial community, while a larger amount of added straw (> 50% straw added) mainly affects the composition of the fungal community. Returning a large amount of straw increases the microbial abundance related to carbon and iron cycles in the paddy soil, thus promoting the carbon and iron cycle processes to a certain extent. In addition, network analysis shows that returning a large amount of straw also increases the complexity of the microbial network, which may encourage more microbes to be niche-sharing and comprehensively improve the ecological environment of paddy soil. This study may provide some useful guidance for rice straw returning in northeast China.


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