Using a sensitivity analysis of a weed dynamics model to develop sustainable cropping systems. II. Long-term effect of past crops and management techniques on weed infestation

2012 ◽  
Vol 151 (2) ◽  
pp. 247-267 ◽  
Author(s):  
N. COLBACH ◽  
S. GRANGER ◽  
D. MÉZIÈRE

SUMMARYBoth scientists and farmers are confronted by a similar question: which current and past cropping system components will influence the present weed flora, and how? This information is necessary to optimize both cropping systems for weed control, and quality and cost in surveys and monitoring schemes. The present study addressed these questions with a sensitivity analysis to input variables of a cropping system model,AlomySys, that predicts weed dynamics in interaction with pedo-climatic conditions. The study ranked cropping system components according to their impact on weed infestation in winter wheat, showing for instance that though crop succession was crucial, current and past tillage strategies influenced grass weed densities even more. Crops were not only ranked as a function of the resulting weed risk but the latter was also linked to crop species traits, i.e. crop type, usual sowing period and emergence speed. A previous winterv.spring crop thus increased weed density by 72% in the following winter wheat; a late-sownv.early sown winter crop by 26%, a slowv.fast-emerging winter crop by 17%, and a lower competitive ability by 9%. Similarly, the characteristics of each crop management technique (tillage, catch crop, secondary crop, mowing, mechanical weeding, herbicides, nitrogen fertilizer, manure and harvest) were quantified. For instance, the timing of the first tillage operation was crucial prior to the analysed winter wheat crop while the choice of the tool used even 5 years previously still influenced weed infestation in the current year; a catch crop prior to previous spring sown crops reduced the current infestation regardless of catch crop sowing dates and densities, but the reductive effect could be lost if the field was tilled several times to destroy the catch crop. The advice synthesized here and in a companion paper (Colbach & Mézière 2012). will be valuable to design innovative, integrated cropping systems, indicating (1) which cropping system components to modify to produce the largest effect, (2) for how long past practices must be considered when choosing current options and (3) the optimal options for the different management techniques. Points (1) and (2) are also valuable to identify data to record in surveys, though still resulting in a total of 232 variables. In a second step, these detailed variables were therefore simplified and aggregated to determine a smaller set of 22 synthetic variables easily recorded in surveys, such as the proportion of winter and spring crops during the last 10 years (instead of the actual crop sequence), the proportion of crops sown in summer, early autumn, late autumn, early spring and late spring during the last 5 years (instead of exact sowing dates), the ploughing frequency (instead of ploughing dates and characteristics), the mean number of herbicide sprayings per year (instead of dates), etc. This reduced survey list will reduce the cost of surveys as well as increase the number and quality of surveys as more farmers will be ready to participate and there will be fewer uncertainties in the answers.

Author(s):  
Laura Masilionytė ◽  
Stanislava Maikštėnienė ◽  
Aleksandras Velykis ◽  
Antanas Satkus

The paper presents the research conducted at the Joniškėlis Experimental Station of the Lithuanian Research Centre for Agriculture and Forestry on a clay loam Gleyic Cambisol during the period of 2006–2010. The research investigated the changes of mineral nitrogen in soil growing catch crops during the winter wheat post-harvest period and incorporating their biomass into the soil for green manure. Green manure implications for environmental sustainability were assessed. The studies were carried out in the soil with a low (1.90–2.00%) and moderate (2.10–2.40%) humus content in organic and sustainable cropping systems. The crop rotation, expanded in time and space, consisted of red clover (Trifolium pretense L.) → winter wheat (Triticum aestivum L.) → field pea (Pisum sativum L.) → spring barley (Hordeum vulgare L.) with undersown red clover. Investigations of mineral nitrogen migration were assessed in the crop rotation sequence: winter wheat + catch crops → field pea. Higher organic matter and nitrogen content in the biomass of catch crops were accumulated when Brassisaceae (white mustard, Sinapis alba L.) was grown in a mixture with buckwheat (Fagopyrum esculentum Moench.) or as a sole crop, compared with oilseed radish (Raphanus sativus var. Oleiferus Metzg.) grown with the long-day legume plants blue lupine (Lupinus angustifolius L.). Mineral nitrogen concentration in soil depended on soil humus status, cropping system and catch crop characteristics. In late autumn there was significantly higher mineral nitrogen concentration in the soil with moderate humus content, compared with soil with low humus content. The lowest mineral nitrogen concentration in late autumn in the 0–40 cm soil layer and lower risk of leaching into deeper layers was measured using organic cropping systems with catch crops. The highest mineral nitrogen concentration was recorded in the sustainable cropping system when mineral nitrogen fertilizer (N30) was applied for winter wheat straw decomposition. In the organic cropping system, the incorporation of catch crop biomass into soil resulted in higher mineral nitrogen reserves in soil in spring than in the sustainable cropping system, (mineral nitrogen fertilizer (N30) applied for straw decomposition in autumn and no catch crop grown). Applying organic cropping systems with catch crops is an efficient tool to promote environmental sustainability.


2012 ◽  
Vol 151 (2) ◽  
pp. 229-245 ◽  
Author(s):  
N. COLBACH ◽  
D. MÉZIÈRE

SUMMARYEnvironmental problems mean that herbicide applications must be drastically reduced and optimized. Models that quantify the effects of crop management techniques on weed dynamics are valuable tools for designing weed management strategies. Indeed, the techniques to be optimized are numerous and diverse, and their effects vary considerably with environmental conditions and the state of the weed flora. In the present study, a mechanistic weed dynamics model,AlomySys, was used to carry outin silicoexperiments in order to: (1) rank crop management components according to the resulting decrease in weed infestation, and (2) study the sensitivity of the major component effects to biophysical field state variables in order to identify indicators and thresholds that could serve for future decision-rules for farmers. The various results were compiled into rules for optimizing timing and other options (tillage tools, herbicide types) for the different crop management techniques. The rules were based on a series of biophysical field state variables, i.e. cumulated rainfall, thermal time, soil moisture and weed densities prior to the operation, in the previous and pre-previous crops. For instance, the first tillage should be delayed until the cumulated rainfall since harvest exceeds 50 mm and be carried out in moist conditions. Mouldboard ploughing is advised if the infestation of the previous crop exceeds 20 weeds/m2and particularly if this exceeds 0·3 times that of the pre-previous crop. Ploughing should occur when the cumulated rainfall since harvest reaches 100–200 mm. The effects of crop succession and long-term effects of management techniques have been studied in a companion paper (Colbachet al. 2012).


2018 ◽  
Vol 64 (No. 4) ◽  
pp. 156-163
Author(s):  
Wang Dapeng ◽  
Zheng Liang ◽  
Gu Songdong ◽  
Shi Yuefeng ◽  
Liang Long ◽  
...  

Excessive nitrogen (N) and water input, which are threatening the sustainability of conventional agriculture in the North China Plain (NCP), can lead to serious leaching of nitrate-N (NO<sub>3</sub><sup>–</sup>-N). This study evaluates grain yield, N and water consumption, NO<sub>3</sub><sup>–</sup>-N accumulation and leaching in conventional and two optimized winter wheat-summer maize double-cropping systems and an organic alfalfa-winter wheat cropping system. The results showed that compared to the conventional cropping system, the optimized systems could reduce N, water consumption and NO<sub>3</sub><sup>–</sup>-N leaching by 33, 35 and 67–74%, respectively, while producing nearly identical grain yields. In optimized systems, soil NO<sub>3</sub><sup>–</sup>-N accumulation within the root zone was about 80 kg N/ha most of the time. In the organic system, N input, water consumption and NO<sub>3</sub><sup>–</sup>-N leaching was reduced even more (by 71, 43 and 92%, respectively, compared to the conventional system). However, grain yield also declined by 46%. In the organic system, NO<sub>3</sub><sup>–</sup>-N accumulation within the root zone was generally less than 30 kg N/ha. The optimized systems showed a considerable potential to reduce N and water consumption and NO<sub>3</sub><sup>–</sup>-N leaching while maintaining high grain yields, and thus should be considered for sustainable agricultural development in the NCP.  


Soil Research ◽  
2012 ◽  
Vol 50 (1) ◽  
pp. 58 ◽  
Author(s):  
P. Jiao ◽  
D. Xu ◽  
S. Wang ◽  
Y. Wang ◽  
K. Liu ◽  
...  

Reducing nitrogen (N) loss from agricultural soils as surface runoff is essential to prevent surface water contamination. The objective of 3-year study, 2007–09, was to evaluate surface runoff and N loss from different cropping systems. There were four treatments, including one single-crop cropping system with winter wheat (Triticum aestivum L.) followed by summer fallow (wheat/fallow), and three double-cropping systems: winter wheat/corn (Zea mays L.), wheat/cotton (Gossypium hirsutum L.), and wheat/soybean (Glycine max L. Merrill). The wheat/fallow received no fertiliser in the summer fallow period. The four cropping systems were randomly assigned to 12 plots of 5 m by 2 m on a silty clay soil. Lower runoff was found in the three double-cropping systems than the wheat/fallow, with the lowest runoff from the wheat/soybean. The three double-cropping systems also substantially reduced losses of ammonium-N (NH4+-N), nitrate-N (NO3–-N), dissolved N (DN), and total N (TN) compared with the wheat/fallow. Among the three double-cropping systems, the highest losses of NO3–-N, DN, and TN were from the wheat/cotton, and the lowest losses were from the wheat/soybean. However, the wheat/soybean increased NO3–-N and DN concentrations compared with wheat/fallow. The losses in peak events accounted for >64% for NH4+-N, 58% for NO3–-N, and 41% for DN of the total losses occurring during the 3-year experimental period, suggesting that peak N-loss events should be focussed on for the control of N loss as surface runoff from agricultural fields.


2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Kapila Shekhawat ◽  
S. S. Rathore ◽  
O. P. Premi ◽  
B. K. Kandpal ◽  
J. S. Chauhan

India is the fourth largest oilseed economy in the world. Among the seven edible oilseeds cultivated in India, rapeseed-mustard contributes 28.6% in the total oilseeds production and ranks second after groundnut sharing 27.8% in the India’s oilseed economy. The mustard growing areas in India are experiencing the vast diversity in the agro climatic conditions and different species of rapeseed-mustard are grown in some or other part of the country. Under marginal resource situation, cultivation of rapeseed-mustard becomes less remunerative to the farmers. This results in a big gap between requirement and production of mustard in India. Therefore site-specific nutrient management through soil-test recommendation based should be adopted to improve upon the existing yield levels obtained at farmers field. Effective management of natural resources, integrated approach to plant-water, nutrient and pest management and extension of rapeseed-mustard cultivation to newer areas under different cropping systems will play a key role in further increasing and stabilizing the productivity and production of rapeseed-mustard. The paper reviews the advances in proper land and seedbed preparation, optimum seed and sowing, planting technique, crop geometry, plant canopy, appropriate cropping system, integrated nutrient management and so forth to meet the ever growing demand of oil in the country and to realize the goal of production of 24 million tonnes of oilseed by 2020 AD through these advanced management techniques.


2017 ◽  
Vol 8 (2) ◽  
pp. 364-367 ◽  
Author(s):  
L. Zhou ◽  
G. Chen ◽  
Y. Miao ◽  
H. Zhang ◽  
Z. Chen ◽  
...  

The objective of this study was to evaluate the performance of a Crop Circle sensor-based precision nitrogen (N) management (PNM) strategy in different winter wheat cropping systems under on-farm conditions in North China Plain (NCP). Four farmer’s fields were selected for on-farm experiments in Laoling County, Shandong Province of NCP in 2015-2016. In each field, the PNM strategy was evaluated in two winter wheat cropping systems: farmer’s conventional management (FCM) and regional optimum crop management (ROCM). In each cropping system, there were two N management strategies: 1) FCM or ROCM; 2) PNM. The results indicated that the PNM strategy significantly increased partial factor productivity (PFP) by 29% in the FCM system, but did not have any significant improvement in the ROCM system. The ROCM system, using either regional optimum N management or PNM, significantly increased both grain yield and PFP than the FCM system.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247137
Author(s):  
Muhammad Shahzad ◽  
Khawar Jabran ◽  
Mubshar Hussain ◽  
Muhammad Aown Sammar Raza ◽  
Leonard Wijaya ◽  
...  

The world population will rise in future, which would demand more wheat production to fulfil dietary needs of wheat-dependent population of the world. Food security in wheat-dependent regions will greatly rely on wheat productivity. Weed infestation is a major constraint reducing wheat productivity globally. Nonetheless, cropping systems and weed management strategies strongly influence weed infestation in modern agriculture. Herbicides are the key weed management tool in conventional agriculture. However, frequent use of herbicides have resulted in the evolution of herbicide-resistance weeds, which made weed management a challenging task. Sustainable and eco-friendly weed management strategies shift weed-crop competition in the favour of crop plants. Limited studies have evaluated the interactive effect of cropping systems and weed management strategies on weed flora of wheat-based cropping systems (WBCSs). This two-year study evaluated the impact of different weed management strategies (WMSs) on weed flora of WBCSs, i.e., fallow-wheat (FW), rice-wheat (RW), cotton-wheat (CW), mungbean-wheat (MW) and sorghum-wheat (SW). The WMSs included in the study were, false seedbed, allelopathic water extracts and herbicide application, while weed-free and weedy-check were maintained as control treatments. Data relating to diversity and density of individual and total broadleaved and narrow-leaved weeds were recorded. The WBCSs, WMSs and their interaction significantly altered diversity and density of individual, total, broadleaved and narrow-leaved weeds. Weed-free and weedy-check treatments recorded the lowest and the highest values of diversity and density of individual, total, broadleaved and narrow-leaved weeds. Herbicide application effectively reduced density and diversity of weeds. Allelopathic water extracts and false seedbed proved less effective than herbicides. On the other hand, SW cropping system not only reduced weed density but also limited the weed flora. It is concluded that false seedbed and SW cropping system can be efficiently used to manage weeds in WBCSs. However, long-term studies are needed to infer the impact of SW cropping system and false seedbed on soil properties, soil microbes and productivity of wheat crop.


2020 ◽  
Vol 12 (11) ◽  
pp. 4588
Author(s):  
Huanyuan Wang ◽  
Baoguo Li ◽  
Liang Jin ◽  
Kelin Hu

The North China Plain (NCP) is one of the most important grain production regions in China. However, it currently experiences water shortage, severe nonpoint source pollution, and low water and N use efficiencies (WUE and NUE). To explore sustainable agricultural development in this region, a field experiment with different cropping systems was conducted in suburban Beijing. These cropping systems included a winter wheat and summer maize rotation system for one year (WM), three harvests (winter wheat-summer maize-spring maize) in two years (HT), and continuous spring maize monoculture (CS). Novel ways were explored to improve WUE and NUE and to reduce N loss via the alternative cropping system based on the simulation results of a soil-crop system model. Results showed that the annual average yields were ranked as follows: WM > HT > CS. The N leaching of WM was much larger than that of HT and CS. WUE and NUE were ranked as follows: WM < HT < CS. Comprehensive evaluation indices based on agronomic and environmental effects indicated that CS or HT have significant potential for approaches characterized by water-saving, fertilizer-saving, high-WUE, and high-NUE properties. Once spring maize yield reached an ideal level HT and CS became a high-yield, water-saving, and fertilizer-saving cropping systems. Therefore, this method would be beneficial to sustainable agricultural development in the NCP.


Weed Science ◽  
1986 ◽  
Vol 34 (5) ◽  
pp. 730-734 ◽  
Author(s):  
Loren J. Moshier ◽  
Oliver G. Russ ◽  
Joseph P. O'Connor ◽  
Mark M. Claassen

A 3-yr experiment and a 1-yr experiment in continuous winter wheat (Triticum aestivumL. ‘Newton’) and two 3-yr experiments in continuous grain sorghum [Sorghum bicolorL. (Moench.) ‘Co-op SG-10’ or ‘DeKalb DX-42Y’] were conducted to evaluate selected foliage-applied herbicides for control of honeyvine milkweed [Ampelamus albidus(Nutt.) Britt # AMPAL]. Glyphosate [N-(phosphonomethyl)-glycine] applied at 3.4 kg ae/ha, glyphosate plus dicamba (3,6-dichloro-2-methoxybenzoic acid) applied at 1.7 plus 0.6 kg ae/ha, and glyphosate plus 2,4-D [(2,4-dichlorophenoxy)acetic acid] applied at 1.7 plus 1.1 kg ae/ha in summer between harvesting and planting winter wheat and in spring prior to planting grain sorghum effectively reduced honeyvine milkweed regrowth 1 yr after initial application in both cropping systems. One or two additional annual applications did not provide complete control in either cropping system. Applications of 2,4-D at 2.2 kg ae/ha dicamba at 1.1 kg ae/ha and 2,4-D plus dicamba at 1.1 plus 0.6 kg ae/ha were effective if applied consecutively for 3 yr in continuous winter wheat but not in continuous grain sorghum.


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