scholarly journals Strategies for Weed Suppression and Improving Soil Fertility during Transition to Organic Vegetable Production

2012 ◽  
Vol 22 (2) ◽  
pp. 207-214 ◽  
Author(s):  
Stephanie Wedryk ◽  
Joel Felix ◽  
Doug Doohan ◽  
John Cardina

Farmers view weed management and the risk of lower yields as barriers to transition from conventional to organic agriculture. The 3 years of transition before organic certification can be used to implement strategies to suppress weeds and improve soil fertility. The objective of this research was to evaluate the effects of five organic transition strategies on soil quality, weed suppression, and yield of tomato (Solanum lycopersicum) and potato (Solanum tuberosum) in the first year of organic production. The transition strategies included a tilled fallow, nontreated weedy, high diversity prairie mixture, smother crops, and vegetable rotation. Subplots with and without compost application were also included. Transition strategies affected weed density and biomass in the first organic year with the prairie strategy being the most suppressive of monocotyledonous weeds before potato. Compost application increased plant available nutrients and soil organic matter (OM). The quantity of plant available phosphorus was greatest in the fallow transition strategy (55 mg·kg−1) when compost was applied, while percent soil OM was highest in the prairie (3.2%) and nontreated (3.1%) strategies in comparison with the other strategies. Compost application increased yields of potato and tomato with transition strategy affecting the number and weight of cull potato tubers. The selection of transition strategies before conversion to organic agriculture affected weed pressure, soil quality, and crop production in the first certified organic year.

Author(s):  
H. Haruna

Land use changes from forest into cultivated ecosystems result in negative impact on soil structure and quality. The purpose of this study was to determine effect of land use on soil quality in Afaka forest northern guinea savannah of Nigeria. Land use systems, including natural forest and cultivated land were identified. Eighteen (18) composite disturbed and undisturbed samples were collected from depth of 0-5 and 5-10 cm for analysis of pertinent soil properties in the laboratory using grid procedure. Most physical and chemical properties show relative variations in response to land use types and geomorphic positions. Results  indicate  that the soils had  high degree of weathering potentials, low  to moderate  bulk density at 0-5cm depth values between 1.42 to 1.49 Mg m-3 in  forest and  cultivated land, bulk density of  1.34 and 1.46 1.Mg m-3at 5 -1ocm depth   for forest and  cultivated land respectively. The soil water at 0-5cm depth is from 4.20 to 2.63 cm3/cm3, while at 5-10 cm depth these values vary from 4.32 to 2.13 cm3/cm3 under forest and cultivation land use. The pH (H2O) is 6.9 to 7.16 with low electrical conductivity of 0.13 dS/m(forest) and 0.12 dS/m (cultivation). The CEC of soils is recorded as 8.60 cmol kg-1 (forest) to 8.54 cmol kg-1 (cultivated)whereas  total nitrogen content of 1.21 g kg-1 and 1.11 g kg-1 and available phosphorus of 8.78 mg kg-1 (cultivated) and 5.47 mg kg-1 (forest).. Results indicate that soil fertility parameters were moderate to low for cultivated land and at all slope positions, suggesting that soil fertility management is required in order to make agriculture sustainable on Afaka area.


2015 ◽  
Vol 31 (4) ◽  
pp. 309-317 ◽  
Author(s):  
Anne Pfeiffer ◽  
Erin Silva ◽  
Jed Colquhoun

AbstractA primary challenge of managing vegetable production on a small land base is the maintenance and building of soil quality. Previous studies have demonstrated the benefits of cover crops for improved soil quality; however, small growers struggle to fit cover crops into rotations. Small-scale growers with limited available land are under significant pressure to maximize their saleable yield and often work to maximize output by using intensive cropping practices that may include both early and late season crops, thus limiting the typical shoulder season windows in which cover crops can be grown. In-season living mulches may be an effective strategy to provide small-scale growers the benefits of cover crops with less land commitment than cover crops used in typical rotations. However, research on living mulches is generally not suited to small-scale organic production systems due to the typical reliance on chemical herbicide to suppress mulches. An experiment was designed with the goal of evaluating living mulch systems for space-limited organic vegetable production. In a 2-year study, four living mulch crops (buckwheat (Fagopyrum esculentum), field pea (Pisum sativum), crimson clover (Trifolium incarnatum) and medium red clover (Trifolium pratense)) and a cultivated control with no mulch cover were planted in early spring each year. Snap beans (Phaseolus vulgarisvar. Tavera), transplanted bell peppers (Capsicum annuumvar. Revolution), and transplanted fall broccoli (Brassica oleraceavar. Imperial) were then planted directly into living mulches. During each summer growing season, living mulches and weeds were mown between-rows and hand-weeded in-row approximately every 10–14 days as needed for management. Labor times for mowing and cultivation were found to be higher in all treatments relative to the cultivated control. An inverse relationship between living mulch biomass and weed biomass was observed, demonstrating that living mulches may contribute to weed suppression. However, lower vegetable yields were seen in the living mulch treatments, most likely due to resource competition among vegetables, living mulches and weeds. High pre-existing weed seedbank and drought conditions likely increased competition and contributed to reduced vegetable yield.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Le Van Dang ◽  
Ngo Phuong Ngoc ◽  
Ngo Ngoc Hung

Fruit orchards in the Vietnamese Mekong Delta (VMD) are severely degraded due to many factors, such as low organic matter content, soil acidification, and poor soil management. Organic manures are considered to be a soil conservation measure that decreases soil degradation and acidity. This study aimed to evaluate the impacts of soil organic amendments on the improvement of soil fertility and pomelo productivity. Two soil amendments, namely, chicken manure (CM) and cow dung (CD), were investigated for a period of three years at three pomelo orchards. The soil quality was assessed in two depths (0–20 and 20–50 cm), including the soil pH, electrical conductivity (EC), total nitrogen (Ntot), available phosphorus (Pavail), soil organic matter (SOM), bulk density (BD), and exchangeable cations (Ca, Mg, and K). The results indicated that CD and CM improved soil fertility in topsoil layer (0–20 cm) due to an increase in soil pH, SOM, exchangeable Ca, Ntot, and Pavail. In addition, soil BD significantly reduced after CD and CM were supplied in the three consecutive years of study. The soil quality properties that significantly affected pomelo yield were SOM, Ntot, Pavail, and soil BD. Thus, these soil qualities may be considered as key factors for determining and assessing soil quality in fruit orchards in the VMD. More studies on the influence of organic manures on nutrient uptake and pomelo fruit quality are warranted.


2002 ◽  
Vol 12 (4) ◽  
pp. 590-596 ◽  
Author(s):  
Mathieu Ngouajio ◽  
Milton E. McGiffen

Organic agriculture is growing in importance worldwide. In the United States, the rate of increase of organic growers was estimated at 12% in 2000. However, many producers are reluctant to undertake the organic transition because of uncertainty of how organic production will affect weed population dynamics and management. The organic transition has a profound impact on the agroecosystem. Changes in soil physical and chemical properties during the transition often impact indirectly insect, disease, and weed dynamics. Greater weed species richness is usually found in organic farms but total weed density and biomass are often smaller under the organic system compared with the conventional system. The improved weed suppression of organic agriculture is probably the result of combined effects of several factors including weed seed predation by soil microorganisms, seedling predation by phytophagus insects, and the physical and allelopathic effects of cover crops.


Author(s):  
Kang Ma ◽  
Yuxiu Zhang ◽  
Mengying Ruan ◽  
Jing Guo ◽  
Tuanyao Chai

Underground coal mining in western China causes heavy land subsidence and alters the soil ecology. However, the effects of land subsidence on soil fertility are not currently known, and the key factors governing its impact remain unclear in sandy land. We investigated the effects of land subsidence induced by underground mining on the soil quality in western China. Soil samples were collected at 0–15 cm and 15–30 cm from control and subsidence areas in three coal mines. The results showed that the soil water content (SWC), clay and silt percentage, total nitrogen (TN), dissolved organic carbon (DOC), ammonia nitrogen (NH4+-N), nitrate nitrogen (NO3--N), available phosphorus (AP), and available potassium (AK) of the subsidence areas were significantly lower than those of the control areas. The saccharase, urease, and alkaline phosphatase activities in the subsidence areas decreased compared to those in the control areas, while the sand percentage of soil tended to increase. Soil nutrient contents, bacterial quantities, and activities of soil enzymes were positively correlated with SWC. Redundancy analysis (RDA) showed that the soil particle size distribution, SWC, and electrical conductivity (EC) were the major environmental factors driving changes in soil properties. These results indicated that land subsidence induced by coal mining caused losses in surface soil water and nutrients, and ultimately led to soil quality degradation. Therefore, the reclamation of mining subsidence land might be necessary, especially in arid and semi-arid areas.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Songhe Chen ◽  
Rencai Gao ◽  
Xiaoling Xiang ◽  
Hongkun Yang ◽  
Hongliang Ma ◽  
...  

AbstractMicrobe-mediated ammonia oxidation is a key process in soil nitrogen cycle. However, the effect of maize straw mulching on the ammonia oxidizers in the alkaline purple soil remains largely unknown. A three-year positioning experiment was designed as follows: straw mulching measures as the main-plot treatment and three kinds of nitrogen application as the sub-plot treatment. We found the contents of soil organic carbon (SOC), total nitrogen (TN), available potassium (AK), available nitrogen (AN), available phosphorus (AP), and NH4+-N were increased after straw mulching and nitrogen application in alkaline purple soil, so did the amoA genes abundance of ammonia-oxidizing archaeal (AOA) and bacterial (AOB). Terminal restriction fragment length polymorphism (T-RFLP) analysis revealed that Thaumarchaeote (448-bp T-RF) was dominated the AOA communities, whereas Nitrosospira sp (111-bp T-RF) dominated the AOB communities. The community compositions of both AOA and AOB were altered by straw mulching and nitrogen application in alkaline purple soil, however, the AOB communities was more responsive than AOA communities to the straw mulching and nitrogen application. Further analysis indicated that SOC and AP were the main factors affecting the abundance and community compositions of AOA and AOB in alkaline purple soil. The present study reported that straw mulching and nitrogen strategies differently shape the soil ammonia oxidizers community structure and abundance, which should be considered when evaluating agricultural management strategies regarding their sustainability and soil quality.


2021 ◽  
Vol 13 (7) ◽  
pp. 3957
Author(s):  
Yingying Xing ◽  
Ning Wang ◽  
Xiaoli Niu ◽  
Wenting Jiang ◽  
Xiukang Wang

Soil nutrients are essential nutrients provided by soil for plant growth. Most researchers focus on the coupling effect of nutrients with potato yield and quality. There are few studies on the evaluation of soil nutrients in potato fields. The purpose of this study is to investigate the soil nutrients of potato farmland and the soil vertical nutrient distributions, and then to provide a theoretical and experimental basis for the fertilizer management practices for potatoes in Loess Plateau. Eight physical and chemical soil indexes were selected in the study area, and 810 farmland soil samples from the potato agriculture product areas were analyzed in Northern Shaanxi. The paper established the minimum data set (MDS) for the quality diagnosis of the cultivated layer for farmland by principal component analysis (PCA), respectively, and furthermore, analyzed the soil nutrient characteristics of the cultivated layer adopted soil quality index (SQI). The results showed that the MDS on soil quality diagnosis of the cultivated layer for farmland soil included such indicators as the soil organic matter content, soil available potassium content, and soil available phosphorus content. The comprehensive index value of the soil quality was between 0.064 and 0.302. The SPSS average clustering process used to classify SQI was divided into three grades: class I (36.2%) was defined as suitable soil fertility (SQI < 0.122), class II (55.6%) was defined as moderate soil fertility (0.122 < SQI < 0.18), and class III (8.2%) was defined as poor soil fertility (SQI > 0.186). The comprehensive quality of the potato farmland soils was generally low. The proportion of soil nutrients in the SQI composition ranged from large to small as the soil available potassium content = soil available phosphorus content > soil organic matter content, which became the limiting factor of the soil organic matter content in this area. This study revolves around the 0 to 60 cm soil layer; the soil fertility decreased gradually with the soil depth, and had significant differences between the respective soil layers. In order to improve the soil nutrient accumulation and potato yield in potato farmland in northern Shaanxi, it is suggested to increase the fertilization depth (20 to 40 cm) and further study the ratio of nitrogen, phosphorus, and potassium fertilizer.


2011 ◽  
Vol 26 (4) ◽  
pp. 342-353 ◽  
Author(s):  
David Bruce Lewis ◽  
Jason P. Kaye ◽  
Randa Jabbour ◽  
Mary E. Barbercheck

AbstractWeed management is one of the primary challenges for producers transitioning from conventional to organic agriculture. Tillage and the use of cover crops are two weed control tactics available to farmers transitioning to organic management, but little is known about their interactive effects on soil quality during the transition period. We investigated the response of soils to tillage and initial cover crop during the 3-year transition to organic in a cover crop–soybean (Glycine max)–maize (Zea mays) rotation in the Mid-Atlantic region of the USA. The tillage treatment contrasted full, inversion tillage with moldboard plowing (FT) versus reduced tillage with chisel plowing (RT). The cover crop treatment contrasted annual versus mostly perennial species during the first year of the rotation. The experiment was initiated twice (Start 1 and Start 2), in consecutive years in adjacent fields. By the end of the experiment, labile carbon, electrical conductivity, pH and soil moisture were all greater under RT than under FT in both starts. Soil organic matter and several other soil attributes were greater under RT than under FT in Start 1, but not in Start 2, perhaps owing to differences between starts in initial field conditions and realized weather. Soil attributes did not differ between the two cover crop treatments. Combining our soils results with agronomic and economic analyses on these plots suggests that using RT during the organic transition can increase soil quality without compromising yield and profitability.


2020 ◽  
Vol 10 (4) ◽  
pp. 580-593
Author(s):  
M A. Bryzgalina ◽  

The demand for organic food is a prerequisite for the formation and development of organic agriculture, and the task of promoting it on domestic and foreign markets is among the priority ones. A serious problem in the sale of this category of goods to the domestic food markets of the country is the distrust of potential consumers. It is possible to solve this problem through certification and the use of a well-known brand. Certification of manufacturers of environmentally friendly products is a rather complicated and expensive procedure, therefore it is not available for most agricultural producers in the Saratov region. However, basing on the fact that today the task of developing the organic agriculture industry is set at the level of the government of the country, it is possible to solve this problem with the support of the state. The article examines the enterprises of the Saratov region of various legal forms, which do not use fertilizers and chemical means of crop protection in the production of crop production. Using the example of agricultural organizations and farms in the region, a mechanism for subsidizing certification of the most promising producers of organic wheat (winter and spring) is proposed, which includes the allocation of targeted subsidies for its implementation. As a criterion for the selection of applicants for this type of state support, as well as the distribution of budgetary resources between them, it is proposed to use the average indicator (potential) of the annual volume of organic production in the work. As a result, direct participants in certification subsidies were selected from the compiled sample of the studied enterprises that do not use chemical plant protection products and mineral fertilizers and the total annual volume of their marketable wheat was determined. The author determined the maximum cost of quality confirmation procedures for one enterprise, taking into account the increasing coefficients per one day of inspection, and also established the largest amount of budgetary resources that may be spent on the implementation of the proposed measure. In order to evaluate the effectiveness of the proposed certification subsidy mechanism, the author developed formulas for determining the selling price of products in the promising organic segment, taking into account its increase by the level of premium premiums.


2020 ◽  
Vol 10 (4) ◽  
pp. 561-579
Author(s):  
A.A. Leksina ◽  
◽  
E.A. Aleshina ◽  

Organic agriculture is a promising and increasingly demanded direction of “greening” agricultural activity, which has a great potential due to natural production technologies. Significant segments of organic products have been formed in the food markets of the developed countries; various institutional systems of the industry have been functioning for decades. Russian agribusiness is globally lagging behind in these matters, but the development of the economic environment has led to the objective necessity of adopting a law and a state standard that would define the requirements for the organic agriculture. Research on the prospects of the Russian food market in the global organic production system is becoming relevant. This work is a two-sided quantitative and qualitative approach to the study of existing production systems of organic food from the standpoint of the results and dynamics, on the one hand, and their organizational and economic structure, on the other. The findings and results are confirmed by the presented and systematized absolute and relative indicators of land areas certified for organic agriculture, the number of market entities, the consumption of organic food per capita and retail sales in the domestic markets. The qualitative characteristic of organic agriculture systems was reflected in constructing a set of schemes that clearly illustrate national features of the conduct methods, state regulation of production and turnover, research support, regulatory and supervisory support of the business under study. As a result, a comparative analysis of the leading world markets for organic food (USA, Germany, Canada and Austria) in comparison with the emerging market of Russia. The study is addressed to the global business community operating in the organic food market and to special research institutions.


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