Predicting the effect of rotation design on N, P, K balances on organic farms using the NDICEA model

2015 ◽  
Vol 31 (5) ◽  
pp. 471-484 ◽  
Author(s):  
Laurence G. Smith ◽  
Davide Tarsitano ◽  
Cairistiona F. E. Topp ◽  
Stephanie K. Jones ◽  
Catherine L. Gerrard ◽  
...  

AbstractThe dynamic model Nitrogen Dynamics in Crop rotations in Ecological Agriculture (NDICEA) was used to assess the nitrogen (N), phosphorus (P) and potassium (K) balance of long-term organic cropping trials and typical organic crop rotations on a range of soil types and rainfall zones in the UK. The measurements of soil N taken at each of the organic trial sites were also used to assess the performance of NDICEA. The modeled outputs compared well to recorded soil N levels, with relatively small error margins. NDICEA therefore seems to be a useful tool for UK organic farmers. The modeling of typical organic rotations has shown that positive N balances can be achieved, although negative N balances can occur under high rainfall conditions and on lighter soil types as a result of leaching. The analysis and modeling also showed that some organic cropping systems rely on imported sources of P and K to maintain an adequate balance and large deficits of both nutrients are apparent in stockless systems. Although the K deficits could be addressed through the buffering capacity of minerals, the amount available for crop uptake will depend on the type and amount of minerals present, current cropping and fertilization practices and the climatic environment. A P deficit represents a more fundamental problem for the maintenance of crop yields and the organic sector currently relies on mined sources of P which represents a fundamental conflict with the International Federation of Organic Agriculture Movements organic principles.

2016 ◽  
Vol 196 ◽  
pp. 357-367 ◽  
Author(s):  
Dilshan Benaragama ◽  
Steven J. Shirtliffe ◽  
Bruce D. Gossen ◽  
Stu A. Brandt ◽  
Reynold Lemke ◽  
...  

Soil Research ◽  
2019 ◽  
Vol 57 (2) ◽  
pp. 200 ◽  
Author(s):  
J. Somasundaram ◽  
M. Salikram ◽  
N. K. Sinha ◽  
M. Mohanty ◽  
R. S. Chaudhary ◽  
...  

Conservation agriculture (CA) including reduced or no-tillage and crop residue retention, is known to be a self–sustainable system as well as an alternative to residue burning. The present study evaluated the effect of reduced tillage coupled with residue retention under different cropping systems on soil properties and crop yields in a Vertisol of a semiarid region of central India. Two tillage systems – conventional tillage (CT) with residue removed, and reduced tillage (RT) with residue retained – and six major cropping systems of this region were examined after 3 years of experimentation. Results demonstrated that soil moisture content, mean weight diameter, percent water stable aggregates (>0.25mm) for the 0–15cm soil layer were significantly (Pmoderately labile>less labile. At the 0–15cm depth, the contributions of moderately labile, less labile and non-labile C fractions to total organic C were 39.3%, 10.3% and 50.4% respectively in RT and corresponding values for CT were 38.9%, 11.7% and 49.4%. Significant differences in different C fractions were observed between RT and CT. Soil microbial biomass C concentration was significantly higher in RT than CT at 0–15cm depth. The maize–chickpea cropping system had significantly (P–1 followed by soybean+pigeon pea (2:1) intercropping (3.50 t ha–1) and soybean–wheat cropping systems (2.97 t ha–1). Thus, CA practices could be sustainable management practices for improving soil health and crop yields of rainfed Vertisols in these semiarid regions.


1979 ◽  
Vol 11 (1) ◽  
pp. 101-105
Author(s):  
B. R. Eddleman ◽  
J. E. Moya-Rodriguez

Many decisions made by farm producers are based on expectations. The process of formulating and incorporating these expectations into decision making is difficult when high variability occurs in product prices, crop yields, production costs, or other factors affecting net income. Farm producers may be influenced by a number of goals in selecting combinations of crops to produce and marketing outlets for the crops. Two goals generally held to be important to farm decision makers are maximization of net income and net income stability. Given the price, yield, and cost of production variability characteristics of a farm enterprise and these two goals of farm decision makers, a fundamental problem is to determine what combination of alternative marketing actions can best satisfy the two objectives. A systematic examination of the relationship between the level of net income and net income variability for combinations of marketing alternatives would aid farmers in deciding on marketing actions to attain these goals.


2020 ◽  
Vol 2 ◽  
Author(s):  
Nathalie Colbach ◽  
Sandrine Petit ◽  
Bruno Chauvel ◽  
Violaine Deytieux ◽  
Martin Lechenet ◽  
...  

The growing recognition of the environmental and health issues associated to pesticide use requires to investigate how to manage weeds with less or no herbicides in arable farming while maintaining crop productivity. The questions of weed harmfulness, herbicide efficacy, the effects of herbicide use on crop yields, and the effect of reducing herbicides on crop production have been addressed over the years but results and interpretations often appear contradictory. In this paper, we critically analyze studies that have focused on the herbicide use, weeds and crop yield nexus. We identified many inconsistencies in the published results and demonstrate that these often stem from differences in the methodologies used and in the choice of the conceptual model that links the three items. Our main findings are: (1) although our review confirms that herbicide reduction increases weed infestation if not compensated by other cultural techniques, there are many shortcomings in the different methods used to assess the impact of weeds on crop production; (2) Reducing herbicide use rarely results in increased crop yield loss due to weeds if farmers compensate low herbicide use by other efficient cultural practices; (3) There is a need for comprehensive studies describing the effect of cropping systems on crop production that explicitly include weeds and disentangle the impact of herbicides from the effect of other practices on weeds and on crop production. We propose a framework that presents all the links and feed-backs that must be considered when analyzing the herbicide-weed-crop yield nexus. We then provide a number of methodological recommendations for future studies. We conclude that, since weeds are causing yield loss, reduced herbicide use and maintained crop productivity necessarily requires a redesign of cropping systems. These new systems should include both agronomic and biodiversity-based levers acting in concert to deliver sustainable weed management.


2016 ◽  
Vol 26 (5) ◽  
pp. 604-613 ◽  
Author(s):  
John E. Beck ◽  
Michelle S. Schroeder-Moreno ◽  
Gina E. Fernandez ◽  
Julie M. Grossman ◽  
Nancy G. Creamer

Summer cover crop rotations, compost, and vermicompost additions can be important strategies for transition to organic production that can provide various benefits to crop yields, nitrogen (N) availability, and overall soil health, yet are underused in strawberry (Fragaria ×ananassa) production in North Carolina. This study was aimed at evaluating six summer cover crop treatments including pearl millet (Pennisetum glaucum), soybean (Glycine max), cowpea (Vigna unguiculata), pearl millet/soybean combination, pearl millet/cowpea combination, and a no cover crop control, with and without vermicompost additions for their effects on strawberry growth, yields, nutrient uptake, weeds, and soil inorganic nitrate-nitrogen and ammonium-nitrogen in a 2-year field experiment. Compost was additionally applied before seeding cover crops and preplant N fertilizer was reduced by 67% to account for organic N additions. Although all cover crops (with compost) increased soil N levels during strawberry growth compared with the no cover crop treatment, cover crops did not impact strawberry yields in the first year of the study. In the 2nd year, pearl millet cover crop treatments reduced total and marketable strawberry yields, and soybean treatments reduced marketable strawberry yields when compared with the no cover crop treatment, whereas vermicompost additions increased strawberry biomass and yields. Results from this study suggest that vermicompost additions can be important sustainable soil management strategies for transitional and certified organic strawberry production. Summer cover crops integrated with composts can provide considerable soil N, reducing fertilizer needs, but have variable responses on strawberry depending on the specific cover crop species or combination. Moreover, these practices are suitable for both organic and conventional strawberry growers and will benefit from longer-term studies that assess these practices individually and in combination and other benefits in addition to yields.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1393
Author(s):  
Karin S. Levin ◽  
Karl Auerswald ◽  
Hans Jürgen Reents ◽  
Kurt-Jürgen Hülsbergen

Combining organic farming and biogas production from agricultural feedstocks has been suggested as a way of achieving carbon (C) neutrality in Europe. However, as the long-term effects of C removal for methane production on soil organic carbon (SOC) are unclear, organic farmers in particular have questioned whether farm biogas production will have a positive effect on soil fertility. Eight years of data from an organic long-term field trial involving digestate fertilisation and various crop rotations (CRs) with differing proportions of clover-grass leys were used to calculate C inputs based on the CANDY model, and these modelled changes compared with measured changes in SOC content (SOCc) over the same period. Measured SOCc increased by nearly 20% over the eight years. Digestate fertilisation significantly increased SOCc. Fertilised plots with the highest proportion of clover-grass in the CR had the highest SOCc. The C inputs from clover-grass leys, even if they only made up 25% of the CR, were high enough to increase SOCc, even with the removal of all aboveground biomass and without fertilisation. Our results show that biogas production based on clover-grass leys could be an important part of sustainable farming, improving or maintaining SOCc and improving nutrient flows, particularly in organic farming, while simultaneously providing renewable energy.


2020 ◽  
Vol 12 (3) ◽  
pp. 1062 ◽  
Author(s):  
Francis Azumah Chimsah ◽  
Liqun Cai ◽  
Jun Wu ◽  
Renzhi Zhang

Sustainable food production has long been a priority for mankind and this is being challenged by limited arable land, challenged landscapes, and higher human population growth. China started conservation farming around the 1950’s. However, main Conservation Tillage (CT) research started in 1992. Using a systematic meta-analysis approach, this review aims at examining China’s approach to CT and to characterize the main outcomes of long-term CT research across northern China. Data from organizations in charge of CT research in China showed an improvement in crop yield of at least 4% under double cropping systems and 6% under single cropping systems in dry areas of northern China. Furthermore, long-term CT practices were reported to have improved soil physical properties (soil structure, bulk density, pore size, and aggregate stability), soil nutrient levels, and reduction in greenhouse gas emission. Other benefits include significant increase in income levels and protection of the environment. Limitations to CT practice highlighted in this study include occasional reduction in crop yields during initial years of cropping, significant reduction in total N of soils, increase in N2O emission, and the need for customized machinery for its implementation. Outcomes of CT practice are ecologically and economically beneficial though its limitations are worth cogitating.


Author(s):  
Robert P. Larkin

Crop rotations and the inclusion of cover crops and green manures are primary tools in the sustainable management of soil-borne diseases in crop production systems. Crop rotations can reduce soil-borne disease through three general mechanisms: (1) serving as a break in the host-pathogen cycle; (2) by altering the soil physical, chemical, or biological characteristics to stimulate microbial activity and diversity; or (3) directly inhibiting pathogens through the release of suppressive or toxic compounds or the enhancement of specific antagonists. Brassicas, sudangrass, and related plant types are disease-suppressive crops well-known for their biofumigation potential but also have other effects on soil microbiology that are important in disease suppression. The efficacy of rotations for reducing soil-borne diseases is dependent on several factors, including crop type, rotation length, rotation sequence, and use of the crop (as full-season rotation, cover crop, or green manure). Years of field research with Brassica and non-Brassica rotation crops in potato cropping systems in Maine have documented the efficacy of Brassica green manures for the reduction of multiple soil-borne diseases. However, they have also indicated that these crops can provide disease control even when not incorporated as green manures and that other non-biofumigant crops (such as barley, ryegrass, and buckwheat) can also be effective in disease suppression. In general, all crops provided better disease control when used as green manure vs. as a cover crop, but the addition of a cover crop can improve control provided by most rotation crops. In long-term cropping system trials, rotations incorporating multiple soil health management practices, such as longer rotations, disease-suppressive rotation crops, cover crops, and green manures, and/or organic amendments have resulted in greater yield and microbial activity and fewer disease problems than standard rotations. These results indicate that improved cropping systems may enhance productivity, sustainability, and economic viability.


2009 ◽  
Vol 147 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Q. JING ◽  
H. VAN KEULEN ◽  
H. HENGSDIJK ◽  
W. CAO ◽  
P. S. BINDRABAN ◽  
...  

SUMMARYAbout 0·10 of the food supply in China is produced in rice–wheat (RW) cropping systems. In recent decades, nitrogen (N) input associated with intensification has increased much more rapidly than N use in these systems. The resulting nitrogen surplus increases the risk of environmental pollution as well as production costs. Limited information on N dynamics in RW systems in relation to water management hampers development of management practices leading to more efficient use of nitrogen and water. The present work studied the effects of N and water management on yields of rice and wheat, and nitrogen use efficiencies (NUEs) in RW systems. A RW field experiment with nitrogen rates from 0 to 300 kg N/ha with continuously flooded and intermittently irrigated rice crops was carried out at the Jiangpu experimental station of Nanjing Agricultural University of China from 2002 to 2004 to identify improved nitrogen management practices in terms of land productivity and NUE.Nitrogen uptake by rice and wheat increased with increasing N rates, while agronomic NUE (kg grain/kg N applied) declined at rates exceeding 150 kg N/ha. The highest combined grain yields of rice and wheat were obtained at 150 and 300 kg N/ha per season in rice and wheat, respectively. Carry-over of residual N from rice to the subsequent wheat crop was limited, consistent with low soil nitrate after rice harvest. Total soil N hardly changed during the experiment, while soil nitrate was much lower after wheat than after rice harvest. Water management did not affect yield and N uptake by rice, but apparent N recovery was higher under intermittent irrigation (II). In one season, II management in rice resulted in higher yield and N uptake in the subsequent wheat season. Uptake of indigenous soil N was much higher in rice than in wheat, while in rice it was much higher than values reported in the literature, which may have consequences for nitrogen fertilizer recommendations based on indigenous N supply.


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