Root rot caused by Rhizoctonia bataticola is a serious threat in cotton. Field experiments were conducted to study the influences of intercropping system in cotton with inorganic fertilizer and two ...bioinoculants (Azospirillum and Pseudomonas) on root rot incidence and yield of cotton. The results revealed that among the intercropping systems, cotton intercropping with Sesbania aculeata (1 : 1 ratio) recorded the highest rhizosphere colonization of Pseudomonas fluorescens in the year 2007 and 2008 and the lowest root rot incidence of 1.40, 2.49 and 3.90; 1.02, 2.22 and 5.98% at the vegetative, flowering and maturity stages in the year 2007 and 2008, respectively. From nutrient management practices, integration of Azospirillum and Pseudomonas with 50% recommended dose of NPK recorded the highest rhizosphere colonization of P. fluorescens in both years and the lowest root rot incidence of 1.40, 2.32 and 3.36; 1.07, 2.01 and 5.25% at vegetative, flowering and maturity stages in 2007 and 2008, respectively. Cotton + S. aculeata recorded the maximum number of sympodial branches (23.5 and 20.62/plant in 2007 and 2008, respectively) and the highest seed cotton yield of 2010 and 1894 kg/ha. The highest cotton equivalent yield (CEY) of 2052 and 1895 kg/ha was recorded in cotton + onion system, which was closely followed by cotton + S. aculeata system that had the CEY of 2010 and 1894 kg/ha in 2007 and 2008, respectively. The increased CEY is due to increased cost of onion compared with S. aculeata. Combined application of 100% recommended dose of NPK and bioinoculants recorded the seed cotton yield of 2227 and 1983 kg/ha and CEY of 2460 and 2190 kg/ha in 2007 and 2008, respectively. The lowest root rot incidence and increased yield in cotton + S. aculeata combined with 50% NPK and bioinoculants could be due to synergistic effect among the bioinoculants and S. aculeata.
This study analyzed energy input (direct and indirect), energy output, net-energy output, energy use efficiency, energy intensity, and the energy productivity of oat:pea intercrops as affected by ...sowing ratio (oat:pea (%:%): 100:0, 75:25, 50:50, 25:75, 0:100) and nitrogen (N) fertilization (0, 60, 120 kg N ha−1). The two year field experiment was conducted on a calcaric Chernozem soil in the north-western part of the Pannonian Basin. The results for grain yield showed that pure stands of oat and pea had a higher energy use efficiency and energy intensity than intercrops, indicating that pure stands used the growing factors more efficiently than intercrops. The energy use efficiency was higher in pure pea than pure oat. The energy productivity for the above-ground biomass production was much more affected by the factor N fertilization than by the factor sowing ratio. The highest energy productivity of grain N yield and above-ground biomass N yield was achieved in pure pea stands (0:100). N in plant residues of the zero N fertilization variant required 68% lower technical energy than N from mineral fertilizer. The sowing rate of the intercrops is a management tool to trade-off between the benefits of the in-field biodiversity and energy efficiency.
In a pilot experiment established in a sugar beet growing region the erosive washing away of soil was studied in the years 2006 to 2008. The area is located at an altitude of 246 m with the long-term ...mean precipitation of 500 mm and the mean annual temperature of 8.4 °C. The soils are classified as Chernozem, moderately heavy, loamy, with a good supply of nutrients, humus content of 2.30 % and an alkaline soil reaction. Slope gradient is 12 %, exposition is NE. To study the role of intercrops in erosion control, three variants were established after the harvest of the main crop, two variants with different intercrops and one (control) with no intercrop. These were Variant 1 with Secale cereale L. var. multicaule METZG. ex ALEF., a non-freezing intercrop, Variant 2 with cluster mallow (Malva verticillata L.), a freezing intercrop, and a control variant with no intercrop. In Variant 1 Secale cereale L. var. multicaule was desiccated with the herbicide Roundup in early spring. All the variants involved maize as the main crop. In variants 1 and 2, maize was sown in intercrop residues after seedbed preparation by Vario and a compactor. In Variant 3 maize was sown after conventional seedbed preparation. For assessment of soil conditions soil samples were taken to determine soil physical and chemical properties and water content in the soil. Soil loss by erosion was determined using specially-designed pockets. Erosive washing away of soil was monitored during the entire growing season of maize. The variants in which intercrops were used were found very effective in soil erosion control. In Variant 3 (control) without surface crop residues, the washing away of soil was recorded with each heavy torrential rain. During the all years the total amount of soil loss by erosion in this treatment was 2.25 t . ha−1.
The objective of this experiment was to assess the impact of different planting patterns on light availability for cowpea within the intercrop canopy, as well as to evaluate the corresponding effects ...on cowpea's physiological characteristics and grain yield in maize/cowpea intercropping systems. The experiment utilized a randomized complete block design with four replicates and included six treatments: sole cowpea with 40 kg N ha
−1
(T1) and 80 kg N ha
−1
(T2), simultaneous sowing of maize and cowpea with 40 kg N ha
−1
(T3) and 80 kg N ha
−1
(T4) and cowpea sown 3 weeks after maize with 40 kg N ha
−1
(T5) and 80 kg N ha
−1
(T6). Results showed that sole cowpea had higher light interception and leaf area index than intercropped maize/cowpea, regardless of sowing date and nitrogen supply. The highest photosynthetic rates of cowpea were observed in the intercropping maize/cowpea sown simultaneously with 40 kg N ha
−1
and sole cowpea with 80 kg N ha
−1
. The water use efficiency of cowpea was found to be higher when intercropped with simultaneously sown maize, regardless of nitrogen supply, with values of 3.23 μmol CO
2
/mmol H
2
O and 3.3 μmol CO
2
/mmol H
2
O for treatments T3 and T4, respectively. Moreover, the highest cowpea grain yield was observed when maize and cowpea were sown simultaneously with the application of 80 kg N ha
−1
(0.99 t ha
−1
), while the lowest yield was obtained when cowpea was sown 3 weeks after maize (0.37 t ha
−1
), irrespective of nitrogen supply. Overall, our findings suggest that maize/cowpea intercropping with simultaneous sowing of maize can enhance the grain yield of cowpea in the Yucatan Peninsula.
Winter cereal:legume intercropping is considered a sustainable arable farming system not only in temperate regions but also in Mediterranean environments. Previous studies have shown that with ...suitable crop stand composition, high grain yield can be achieved. In this study, a life cycle assessment (LCA) of the influence of sowing ratio and nitrogen (N) fertilization on grain nitrogen yield of oat (Avena sativa L.) and pea (Pisum sativum L.) in intercrops was performed to find the optimal design to achieve low environmental impact. This study compared the environmental impact of oat:pea intercrops using agricultural LCA. Monocrops of oat and pea and substitutive intercrops, which were fertilized with different levels of N, were compared. The system boundaries included all the processes from cradle to farm gate. Mass-based (grain N yield) and area-based (land demand for generating the same grain N yield) functional units were used. The results covered the impact categories related to the agricultural LCAs. The ReCiPe 2016 Midpoint and Endpoint characterization model was used for the data expression. According to the results, an unfertilized combination of oat and pea (50%:50%) had the lowest environmental impact in comparison with the other 14 assessed variants and selected impact categories. In the assessed framework, pea monocrops or intensively fertilized oat monocrops can also be considered as alternatives with relatively low impact on the environment. However, an appropriate grain N yield must be reached to balance the environmental impact resulting from the fertilizer inputs. The production and use of fertilizers had the greatest impact on the environment within the impact categories climate change, eutrophication, and ecotoxicity. The results indicated that high fertilizer inputs did not necessarily cause the highest environmental impact. In this respect, the achieved grain N yield level, the choice of allocation approach, the functional unit, and the data expression approach played dominant roles.
The long-term research conducted in 2002-2017 in a long stationary experiment on studying different types of field crop rotations under conditions of the Kirov region showed that on sod-podzolic ...soils the loss of humus could be lowered using agro technical methods. The most critical of them include the reduction of a portion of bare fallow, transition to sown and green-manure fallow, expanded use of perennial legume and grain-legume crops and intercrop sowings. In eight-field crop rotations when using such means of a biologization as plowing of the root-stubble residues, aboveground mass of green-manure crops in fallow fields and intercrop sowings, the supply of organic substance was within 17.24-83.03 t/ha. By mineral-ization of this substance 7.64-11.51 t of humus were produced. In a crop rotation with bare fallow there is a negative balance of humus of -0.06 t/ha. The positive balance is obtained when using sown, green-manure fallows, intercrop sowings (two-three fields), and introduction of up to 25% perennial legumes to the structure of crop rotations. The formation of 0.96-1.44 t/ha of humus in the arable layer provides positive balance of 0.20-0.72 t/ha. The increase of the part of grain crops up to 62.5-75.0% in the structure of crop rotations resulted in rise of their efficiency up to 4.74-4.79 thousand fodder units. It was 0.27-0.32 thousand fodder units higher than in the control crop rotation with bare fallow. Dependence of productivity of agricultural crops on humus content was insignificantly negative (r = -0.16). The efficiency of the studied crop rotations depended considerably on the amount of productive moisture in the soil in a phase of ear formation of grain crops (r = -0.78) and on biological activity of the soil (r = -0.80).
Coconut palm (
Cocos nucifera
) infestation by
Opisina arenosella
(Lepidoptera: Oecophoridae) in the Indian subcontinent may occur in November to May each year in the same or adjoining areas of ...plantations. Parasitoids of
O. arenosella
may also be consistently present at these times. During other periods, pests and/or parasitoids could be maintained on intercrops that are commonly grown throughout the year. Field surveys of 54 intercrop species in Kerala, India, found that
O. arenosella
attacks banana, but not others, while laboratory screening showed that
O. arenosella
can mature on jack fruit, cashew and oil palm. Larvae of 20 lepidopteran species found on intercrops were screened for use by
Goniozus nephantidis
(Hymenoptera: Bethylidae), a larval parasitoid of
O. arenosella
, which oviposited on two species but its offspring failed to mature. Thirteen intercrop herbivore species were screened for use by
Brachymeria nosatoi
(Hymenoptera: Chalcididae), a pupal parasitoid of
O. arenosella
, which completed development on the pyralids
Herculia nigrivita
,
Syllepte derogata
and
Psara basalis
. Further, connectance trophic webs were compiled using prior field records of coconut, 33 species of intercrops, 58 species of lepidopteran herbivores and 29 species of primary parasitoids. Both laboratory and literature evidence suggests that populations of
O. arenosella
are unlikely to be maintained by feeding on intercrops or strongly influenced by direct competition with other lepidopterans but are likely to be affected by sharing parasitoids. Intercrop herbivores have clear potential for maintaining parasitoids of
O. arenosella,
and we recommend thirteen plant species as intercrops that should aid in conservation biocontrol.
Many agronomic studies have shown the advantages of species mixtures (SM), but for food grain production, they represent only a small niche. Empirical studies that investigate reasons for SM adoption ...in food grain production are scarce. Here we present an in-depth study based on qualitative expert interviews with nine farmers. By means of interpretative analysis and reconstruction, socially shared models of SM adoption were built to identify the five main factors for SM adoption: (1) perceived relative mixture performance compared to sole crops, (2) suitability within the farm context (3), challenges and opportunities in mixture management due to increased complexity, (4) knowledge and technology as resources to handle mixture management and (5) quality standards in the food value chain. Relative performance was perceived as higher for SM than for sole crops for crop protection, nutrient efficiency, farm diversification, total yield stability and grain quality. The yield stability of individual crop species in SM was perceived as lower and grain impurities higher, requiring increased separation efforts. The economic potential of SM was perceived as highly variable, depending on crop value and post-harvest efforts to attain food quality. Reconstructing the mixture management process revealed that the interspecific plant interactions and emergent mixture attributes increased the cropping system complexity and affected the entire farming process. Adopting SM required knowledge about species interactions, mixture attributes and equipment settings. Large knowledge gaps for food SM were identified. The complexity of SM also provided opportunities for farmers to design mixtures that allow competition control (alternate rows) or avoid separation (relay mixtures). The main conclusions are: (1) increased complexity is a basic property of SM compared to sole crops, enabling advantages and increasing the option space to develop new sustainable cropping systems, (2) specific knowledge and technology are required for SM and are not accessible for most farmers, requiring new information channels and (3) new food SM should be developed more systematically, taking into account mixture properties and their effects on the farming process, as well as needs from the food value chain.
This study evaluated the concurrent application and the results of the root electrical capacitance (CR) and minirhizotron (MR) methods in the same plant populations. The container experiment involved ...three winter wheat cultivars, grown as sole crops or intercropped with winter pea under well-watered or drought-stressed conditions. The wheat root activity (characterized by CR) and the MR-based root length (RL) and root surface area (RSA) were monitored during the vegetation period, the flag leaf chlorophyll content was measured at flowering, and the wheat shoot dry mass (SDM) and grain yield (GY) were determined at maturity. CR, RL and RSA exhibited similar seasonal patterns with peaks around the flowering. The presence of pea reduced the maximum CR, RL and RSA. Drought significantly decreased CR, but increased the MR-based root size. Both intercropping and drought reduced wheat chlorophyll content, SDM and GY. The relative decrease caused by pea or drought in the maximum CR was proportional to the rate of change in SDM or GY. Significant linear correlations (R2: 0.77–0.97) were found between CR and RSA, with significantly smaller specific root capacitance (per unit RSA) for the drought-stress treatments. CR measurements tend to predict root function and the accompanying effect on above-ground production and grain yield. The parallel application of the two in situ methods improves the evaluation of root dynamics and plant responses.
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