Intercropping Model Research Articles

Determination of the Effects of Pear-Morchella Intercropping Mode on M. sextelata Quality, Yield, and Soil Microbial Community.

The intercropping of Morchella in pear orchards has important production value in improving the utilization rate and economic benefits of the orchard; however, there is little research on the intercropping model of pear-Morchella. In this study, metabolomics analysis found that compared with greenhouse cultivation, there were 104 and 142 metabolites significantly increased and decreased in the intercropping mode of M. sextelata, respectively. Among them, there was a significant accumulation of amino acids (phenylalanine, lysine, proline, citrulline, and ornithine), sugars (arabinitol and glucosamine), and organic acids (quinic acid, fumaric acid, and malic acid) related to the unique taste of Morchella in intercropping cultivation. In addition, research on the cultivation model using exogenous nutrient bags indicated that placing the density of six exogenous nutrient bags per square meter was most suitable for yield formation. Adding pear sawdust to the nutrient bags (PN) significantly increased the yield of morel per unit area. Moreover, soil microbial community analysis showed that fungal alpha diversity dramatically declined in PN-cultivated soil, which decreased the relative abundance of soil-borne fungal pathogens, including Fusarium and Aspergillus. Some beneficial soil bacteria abundance increased in the PN-used soil, such as Pedobacter, Pseudomonas, and Devosia. This study provides novel insights into the effects of intercropping on the internal quality of Morchella and enriches the theoretical knowledge on the consummation of the pear-Morchella model formation, further improving agricultural resource utilization efficiency and crop productivity.

Boosting farm resilience: Integrating vegetables and spices in nutmeg and arecanut agroforestry

Experiments were conducted to develop a suitable intercropping model under a nutmeg and areca nut-based mixed farming system for higher productivity in the Thondamuthur region of Coimbatore district of Tamil Nadu. Coriander cv.CO4, Fenugreek cv.CO2, Okra hybrid Co 4, Cluster beans cv. MDU 1, Vegetable cowpea cv.PKM 1, Lablab (bush type) Co(Gb-16)) and Small onion cv.CO 4 was intercropped under 14-year-old Arecanut and 18-year-old Nutmeg trees. The design followed was RBD with three replications. Results revealed that the growth and yield of intercrops were reduced under intercropping compared to pure cropping. Among the intercrops, okra was the least affected, yielding 19.8t/ha, 7.78% lower than pure cropping. Coriander and fenugreek were the most affected. The yield of coriander and fenugreek was 0.43 and 0.47 t/ha, respectively 24.88% and 25.05% lower than pure cropping. The growth of nutmeg and areca nut trees were also influenced due to intercropping with vegetable cowpeas. The increment in DBH of nutmeg was maximum (0.52 cm) with vegetable cowpea intercropping and minimum (0.33 cm) with coriander intercropping. The increment in DBH of arecanut was maximum (0.42 cm) with vegetable cowpea intercropping and minimum (0.25 cm) with fenugreek intercropping. The B:C ratio was highest (2.17) under small onion intercropping. Small onion cultivation was successful under nutmeg and arecanut-based mixed farming systems.

Evaluating a new intercrop model for capturing mixture effects with an extensive intercrop dataset

Cereal-legume intercrops have numerous advantages over monocultures. However, the intercrop’s performance depends on the plant genotypes, management, and environment. Process-based agro-ecosystem models are important tools to evaluate the performance of intercrop systems as field experiments are limited in the number of treatments. The objective of this study was to calibrate and evaluate a new process-based intercrop model using an extensive experimental data set and to test whether the model is suitable for comparing intercrop management strategies. The data set includes all combinations of 12 different spring wheat entries (SW, Triticum aestivum L.) with two faba bean (FB, Vicia faba L.) cultivars, at two sowing densities, in three different environments. The results show that the intercrop model was capable of simulating the absolute mixture (intercrop) effects (AME) for grain yield, above-ground biomass, and topsoil root biomass, for both crops. However, the intercrop model does not perform better than a benchmark that ignores the intercrop effects when simulating plant height, fraction of intercepted radiation, volumetric soil water content, and subsoil root biomass. The intercrop model predicted reasonably well the differences between species and between SW cultivars for grain yield and aboveground plant biomass. Overall, the tested process-based model can be a useful tool for designing and pre-evaluation multiple combinations of crop management, species, and cultivars suitable for intercropping in diverse conditions.

Simulation of tomato and corn growth using a modified intercropping model considering radiation interception in two-dimensional space and air temperature stress

Intercropping system has been widely applied in the agricultural production worldwide. However, the difference in agricultural productivity in tomato–corn intercropping system with different spatial arrangements has not been determined. Meanwhile, the existing intercropping models cannot precisely capture inter-species crop growth dynamics. Therefore, a 10-year (2010–2019) experimental field study was conducted in Hetao irrigation district, China, for the parameterization and evaluation of the model. The experiment data from the typical years (2018 and 2019) was adopted to analyze the crop growth dynamics in different hydrological years and different systems [two rows of tomato intercropping two rows of corn (IC2–2), four rows of tomato intercropping two rows of corn (IC4–2), sole corn (SC), and sole tomato (ST)]. Moreover, a modified intercropping model considering radiation interception in two-dimensional space and air temperature stress (MICG) was deduced. The results revealed that the MICG model can precisely simulate inter-species crop growth in tomato–corn intercropping system with different spatial arrangements. The mean relative error (MRE), normalized root mean square error (nRMSE), determination coefficient (R2), and percentage bias (PBIAS) of leaf area index (LAI) simulated by the MICG model in different spatial arrangements were 9.0 %, 7.8 %, 0.97, and –5.3 % for corn and 11.0 %, 7.8 %, 0.95, and 0.1 % for tomato, respectively. An apparent difference in the simulation accuracy was observed among different intercropping models in the rapid and senescence crop growth stages. The simulation accuracy of the MICG model was apparently higher than that of ICGw and ICG models. However, the MICG model still needs to be further improved considering its some limitations, e.g., the soil respiration and soil nitrogen transformation modules need be introduced in this model. Additionally, an apparent difference in crop growth dynamics in different spatial arrangements was observed, particularly in different hydrological years. The largest difference in crop growth dynamics in different spatial arrangements was observed in the middle crop growth stage (days after sowing [DAS] 20–100) in the wet year and in the late crop growth stage (DAS 101–140) in the dry year. In general, the highest aboveground biomass and yields of corn and tomato were observed in the IC2–2 and ST systems, respectively. However, the highest water use efficiency for corn (23.9) and tomato (268.7) was observed in the IC4–2 and ST systems, respectively. The agricultural production benefits in the IC4–2 system were better than in the IC2–2 system. Average land equivalent ratio and water equivalent ratio in both years increased by 0.8 % and 12.5 % in the IC4–2 system compared with those in the IC2–2 system, respectively. Overall, the IC4–2 system could be recommended as the most optimal spatial arrangement for the tomato–corn intercropping system.

Phytoremediation and environmental effects of three Amaranthaceae plants in contaminated soil under intercropping systems

Intercropping is a widely used agricultural system; however, the effect of intercropping between accumulator plants on phytoextraction in heavy metal-contaminated soils remains unknown. Here, a field experiment was conducted to investigate the phytoextraction efficiency and related environmental effects of three Amaranthaceae plants (Amaranthus hypochondriacus, Celosia argentea, and Pfaffia glomerata) using mono- and intercropping models. In monocropping, the total biomass of A. hypochondriacus was only 51.2 % of that of C. argentea. Compared with monocropping, intercropping reduced the fresh weight per plant of A. hypochondriacus by 53.0 % (intercropping with C. argentea) and 40.5 % (intercropping with P. glomerata) but increased the biomass per plant of C. argentea and P. glomerata by 128.2 and 14.2 %, respectively. The Cd uptake of the three plants in the monocropping models showed the following trend: C. argentea > P. glomerata > A. hypochondriacus. Interplanting A. hypochondriacus and C. argentea further increased the phytoextraction efficiency by 361.2 % (compared with A. hypochondriacus monocropping) and 52.0 % (compared with C. argentea monocropping). Soil exchangeable Cd, Pb, Cu, Zn, K, and P, soil N-NO3− and N-NH4+, soil common bacteria and arbuscular mycorrhiza (AM) fungi, and soil total organic carbon (TOC) play key roles in Cd and Pb uptake by the three accumulator plants (p < 0.05). The biomass of common bacteria, Gm+, Gm− bacteria, fungi, AM fungi, and actinomycetes increased with the three accumulators planted in the mono- and intercropping models. Compared with C. argentea monocropping, the biomass of soil microbes in the rhizosphere soil was obviously increased in the intercropping A. hypochondriacus and C. argentea models. These results suggest that interplanting A. hypochondriacus and C. argentea can increase Cd removal efficiency from Cd-contaminated soils, and this model could be recommended to remediate Cd-contaminated soils on a field scale.

The application of mixed stabilizing materials promotes the feasibility of the intercropping system of Gynostemma pentaphyllum/Helianthus annuus L. on arsenic contaminated soil

Intercropping technology and stabilizing materials are common remediation techniques for soils contaminated with heavy metals. This study investigated the feasibility of the Gynostemma pentaphyllum (G. pentaphyllum)/Helianthus annuus L. (H. annuus) intercropping system on arsenic (As) contaminated farmland through field and pot experiments and the regulation of plant As absorption by the application of mixed stabilizing materials in this intercropping system. Field experiments demonstrated that intercropping with H. annuus increased the As concentration in G. pentaphyllum leaves to 1.79 mg kg−1 but still met the requirements of the national food standard of China (2 mg kg−1) (GB2762-2017). Meanwhile, G. pentaphyllum yield in the intercropping system decreased by 15.09%, but the difference was insignificant (P > 0.05). Additionally, the As bioconcentration (BCA) per H. annuus plant in the intercropping system was significantly higher than that in the monoculture system, increasing by 76.37% (P < 0.05). The pot experiment demonstrated that when granite powder, iron sulfate mineral, and "Weidikang" soil conditioner were applied to the soil collectively, G. pentaphyllum leaf As concentration in the intercropping system could be significantly reduced by 42.17%. Rhizosphere pH is the most crucial factor affecting As absorption by G. pentaphyllum in intercropping systems. When these three stabilizing materials were applied simultaneously, the As bioaccumulation (BCA) per H. annuus plant was significantly higher than that of normal intercropping treatment, which increased by 71.12% (P < 0.05), indicating that the application of these stabilizing materials significantly improved the As removal efficiency of the intercropping system. Dissolved organic carbon (DOC) concentration in the rhizosphere soil is the most pivotal factor affecting As absorption by H. annuus. In summary, the G. pentaphyllum-H. annuus intercropping model is worthy of being promoted in moderately As polluted farmland. The application of granite powder, iron sulfate mineral, and "Weidikang" soil conditioner collectively to the soil can effectively enhance the potential of this intercropping model to achieve "production while repairing" in the As polluted farmland.

Agronomic and socio-economic options for rubber intercropping in Sri Lanka: a forward analysis in the Moneragala and Ampara regions

Natural rubber is considered a strategic material for the development of Sri Lanka by the Ministry for Plantations. In response to climate change, the country has adopted a policy focusing on resilience and sustainable development. It is in this context that Ksapa initiated the RIVER project in 2022, aiming to develop a program to strengthen agricultural capacity in Sri Lanka. To carry out this project, the company commissioned YAPI Expertise to provide agroforestry intercropping models based on rubber trees with good agronomic performance and economically of interest to producers to diversify their sources of income. The RIVER project is implemented in two districts in south-eastern Sri Lanka: Moneragala and Ampara. This study began with an analysis of the literature in order to select crops that could be intercropped with rubber. In parallel, 80 interviews, prepared by YAPI Expertise, were conducted in the field by a local organisation, LOAM. The aim of these interviews was to identify rubber intercrop models already implemented in the study areas and to understand the reasons why farmers adopted these models. The interviews were analysed statistically by MCA and Chi². By combining these with the literature review, the study established 5 models (Pineapple model, Cocoa model, Banana model, Passion fruit model, Soursop model) for several intercrops that could be planted with rubber, with potential for adoption by local farmers. Finally, selection criteria were established for each model. Both their strong and weak points are presented, since an effective model cannot rely on agronomic analysis alone and it will be essential to adapt the choice of crops to the local market and to farmers' needs.

Development of a Cereal–Legume Intercrop Model for DSSAT Version 4.8

Intercropping is extensively used to increase land productivity and agricultural benefits. In developing countries, intercropping has historically been one of the most widely used cropping systems. Crop models have been used to assess risk productivity over time and space, particularly in monocropping systems. Crop models, such as the Decision Support System for Agrotechnology Transfer (DSSAT), have been widely used to improve crop growth, development, and yield predictions; however, this model has some limitations when assessing interspecific competition in intercropping systems (e.g., it does not have a subroutine capable of running two crops simultaneously). Therefore, in this study, we developed a new approach to allow DSSAT to run two crop species in intercropping systems. A light interception algorithm and modified source code were integrated into the DSSAT to simulate the relay-strip intercropping system. The intercrop model developed in this study is the first intercrop model for DSSAT. This model is generic and can be employed to build other cereal–legume intercrop models for DSSAT Version 4.8. Regarding risk assessment of crop production, the model can evaluate long-term cereal–legume intercrop yields in low-input cropping systems. Therefore, before officially launching the new model in DSSAT, more field trials are recommended to rigorously evaluate and improve the model with data from different environments. The intercrop model developed in this study is simple, so this modeling approach can be employed to develop other cereal–noncereal intercrop models.

Crop Productivity, Economic Advantage, and Photosynthetic Characteristics in a Corn-Peanut Intercropping System

Corn-peanut intercropping is an important element of China’s agricultural planting model as it confers ecological benefits and increases yield. The aim of this study was to explore the productivity differences between intercropping and monoculture by using the 13C isotope tracer labelling method. Corn hybrid Denghai 618 (DH618) and peanut variety Huayu 22 (HY22) were used as test materials under three planting methods, single corn, SM; single peanut, SP; and corn-peanut intercropping, IM and IP, respectively, during two growing seasons. The results showed that IM increased yield by 59.7% and 62.3% compared with SM, respectively. IP reduced yield by 31.3% and 32.3% compared with SP, respectively. IM significantly increased the photosynthetic rate, leaf area, 13C assimilation distribution, and dry matter accumulation of summer corn, which led to an increase in the kernel number and grain yield. The decrease in intercropped peanut yield was mainly caused by a decrease in the full-pod rate and number of pods per plant. The decrease in peanut yield did not affect the production of intercropping benefit due to the larger intercropping advantage and land equivalence ratio. Corn-peanut intercropping yielded greater economic benefits than monoculture. These results showed the utility of the peanut-corn intercropping model.

Characteristics of Soil Physicochemical Properties and Microbial Community of Mulberry (Morus alba L.) and Alfalfa (Medicago sativa L.) Intercropping System in Northwest Liaoning

Medicinal plant intercropping is a new intercropping method. However, as a new intercropping model, the influence of intercropping of alfalfa on microorganisms has not been clarified clearly. In this study, the composition and diversity of microbial communities in alfalfa intercropping were studied, and the differences of bacterial and fungal communities and their relationships with environmental factors are discussed. Intercropping significantly decreased soil pH and significantly increased soil total phosphorus (TP) content, but did not increase soil total carbon (TC) and total nitrogen (TN). Intercropping can increase the relative abundance of Actinobacteria and reduce the relative abundance of Proteobacteria in soil. The relative abundance and diversity of bacteria were significantly correlated with soil pH and TP, while the diversity of fungi was mainly correlated with TC, TN and soil ecological stoichiometry. The bacterial phylum was mainly related to pH and TP, while the fungal phylum was related to TC, TN, C: P and N: P. The present study revealed the stoichiometry of soil CNP and microbial community characteristics of mulberry-alfalfa intercropping soil, clarified the relationship between soil stoichiometry and microbial community composition and diversity, and provided a theoretical basis for the systematic management of mulberry-alfalfa intercropping in northwest Liaoning.

Resource sharing in intercropping models and a case study with APSIM in southern Australia

Various benefits of intercropping systems have been reported worldwide. However, fewer modeling studies of these systems have been undertaken. We present key intercropping features and processes in seven intercropping models, highlighting strengths and limitations. Representation of key processes such as resource sharing and plasticity are a challenge in modeling. Very few studies have investigated plasticity, focusing mainly on crop response to light. Therefore, further research is necessary to understand and incorporate these key processes in intercropping models. We selected APSIM to evaluate its ability to simulate the intercropping effects by 1) a theoretical combination of crops and crop densities and (2) a comparison against observed data in three locations in Victoria, Australia. Models for monocultures and intercrop combinations with varying crop density ratios for four crops (barley, canola, fababean and wheat) were calibrated and the model performance was evaluated. Simulated monoculture results were satisfactory but intercropping results were poor. The growth of intercrops was found to depend on interactions between the parameter KL (fraction of plant available water extracted daily) and soil water content whose dynamics in turn depended on the method and amount used to initialize soil water. The resource sharing ‘alternate day’ approach in the model may not be suitable in water-limited environments because it can lead to excessive advantage of one intercrop over the other. Incorporating intercrop-specific parameters, representation of plant density ratios and revising resource sharing algorithms in the model may improve results.

Integrated Starches and Physicochemical Characterization of Sorghum Cultivars for an Efficient and Sustainable Intercropping Model.

Sorghum has good adaptation to drought tolerance and can be successfully cultivated on marginal lands with low input cost. Starch is used in many foods and nonfood industrial applications and as a renewable energy resource. Sorghum starches with different amylose contents affect the different physicochemical properties. In this study, we isolated starches from six sorghum varieties (i.e., Jinza 34, Liaoza 19, Jinnuo 3, Jiza 127, Jiniang 2, and Jiaxian) and investigated them in terms of their chemical compositions and physicochemical properties. All the starch granules had regular polygonal round shapes and showed the characteristic “Maltese cross”. These six sorghum starches showed an A-type diffraction pattern. The highest amylose content of starch in Jinza 127 was 26.90%. Jiaxian had a higher water solubility at 30, 70, and 90 °C. From the flow cytometry analysis based on six sorghum starch granules, Liaoza 19 had a larger and more complex granules (particle percentage (P1) = 66.5%). The Jinza 34 starch had higher peak (4994.00 mPa∙s) and breakdown viscosity (4013.50 mPa∙s) and lower trough viscosity (973.50 mPa∙s). Jinnuo 3 had higher onset temperature, peak temperature, conclusion temperature, gelatinization enthalpy, and gelatinization range. The principal component analysis and hierarchical cluster analysis based on classification of different sorghum starches showed that Jiniang 2 and Jinnuo 3 had similar physicochemical properties and most divergent starches, respectively. Our result provides useful information not only on the use of sorghum starches in food and non-food industries but for the great potential of sorghum-based intercropping systems in maintaining agricultural sustainability.

Effects of relay intercropping model and application of biological agents on the growth and yield of hot pepper

Tiyung cultivar, the consumer preferences of hot pepper in Magelang Regency, is still low in productivity (7 ton.ha-1). This research aimed to determine the growth and yield of hot pepper planted in relay intercropping as affected by biological agent application as a technology to increase productivity. This research was arranged in a Factorial Randomized Complete Block Design with an intercropping pattern of hot pepper (two and three rows model). The second factor was the application of biological agents, consisting of Trichoderma asperellum, Bacillus velezensis B-27 and Arbuscular Mycorrhizal Fungi (with and without biological agents). The control was the monoculture of hot pepper without biological agent application. The data observed were analyzed using Analysis of Variance and followed by the Duncan's Multiple Range Test at α= 5 %. The results showed that the relay intercropping of hot pepper produced less numbers of branches and leaves. It indicated more efficiency in the use of assimilates for the development of generative organs, thereby resulting in the high values fruits weight per plant, which were as high as those in monoculture. The productivity observed in relay intercropping was 12.93 ton.ha-1, which was 15.8 % higher than in monoculture. The application of biological agents significantly increased the stomatal density, the size of stomatal opening, the number of leaves, weight of fruits per plant and productivity of hot pepper. The productivity of plant applied with biological agents was 16.84 ton.ha-1, which was 86.50 % higher than that without biological agents application.

Effects of Different Intercropping Models on Growth and Yield Traits of Maize in Red Soil Dryland

In order to develop the suitable planting mode of maize in red soil dryland, improve the related plant and ear characters of maize, promote high quality and high yield, and improve economic benefits. The experiment was conducted in the Science and Technology Park of Jiangxi Agricultural University from May 13, 2020 to October 18, 2020 and from May 5, 2021 to October 7, 2021. Taking maize as the control, three intercropping treatments of maize intercropping soybean, maize intercropping peanut and maize intercropping sweet potato were set up to compare their effects on agronomic characters such as plant height, stem diameter and ear width of maize and yield. The results showed that the plant height and ear height of maize intercropping soybean reached the maximum in two years, with plant height of 208.9 cm and 191.9 cm, ear height of 80.2 cm and 58.4 cm, respectively. The ear length and grain number per row of intercropping treatment were better than that of monoculture treatment. The ear length of maize intercropping and soybean reached the maximum, which were 16.5 cm and 19.0 cm respectively, and the grain number per row was also higher than that of other treatments. The yield of maize intercropping soybean was the highest, 42.1 kg and 43.5 kg respectively in two years. Compared with monoculture, intercropping can improve stem diameter, ear height, ear length, grain number per row and other ear traits, so as to improve corn yield, among which maize intercropping soybean is the best. The results of grey correlation showed that ear length and plant height had a great influence on maize yield. The comprehensive analysis shows that the use of maize intercropping soybean model is conducive to achieve high quality and high yield.

Effects of Fallopia multiflora–Andrographis paniculata intercropping model on yield, quality, soil nutrition and rhizosphere microorganisms of F. multiflora

Effects of Fallopia multiflora–Andrographis paniculata intercropping model on yield, quality, soil nutrition and rhizosphere microorganisms of F. multiflora

SISTEM REPLANTING KELAPA SAWIT, OPPORTUNITY PENDAPATAN KELAPA SAWIT DAN TINGKAT KESEJAHTERAAN PETANI PADA MASA REPLANTING DI PERKEBUNAN KELAPA SAWIT RAKYAT KABUPATEN LAMPUNG TENGAH

This study aims were to determine the replanting model used by oil palm farmers, to calculate the replanting cost, to know the opportunity lost income, and to analyze the level of welfare of farmers during replanting in Central Lampung Regency. The sampling technique was a survey. The study was conducted in three districts, Anak Tuha District, Bangun Rejo District, and Sendang Agung District. The respondents were 31 oil palm farmers consisting of 6 respondents from Anak Tuha District, 21 respondents from Bangun Rejo District, and 4 respondents from Sendang Agung District. The data collection was carried out in March-May 2019. The results showed tha the replanting model used by oil palm farmers in Central Lampung Regency was the intercropping model with food crops and the underplanting model. The costs of replanting during the first 3 years when the palm trees are not productive yet were IDR45,481,990 per hectare on the intercropping model and IDR 48,146,117 per hectare on the underplanting model. The average value of oil palm opportunity lost income the intercropping model with food crops was IDR7,672,043 per hectare. The average household income of oil palm farmers was IDR19,489,145 per year. The level of welfare of farmers during replanting in Central Lampung Regency in general is in a fairly decent condition. Key words: cost, income, oil palm, opportunity, replanting, welfare

Maximizing Land Use Efficiency and Productivity of Soybean and Fodder Maize Intercrops through Manipulating Sowing Schedule and Maize Harvest Regime

The incorporation of both food and forage crops in an intercropping system is receiving increasing attention, especially in developing countries with increasing populations and limited resources. In a two-year (2019–2020) field trial, conducted in Northern Egypt, productivity of soybean and fodder maize, as well as the quality of maize herbage, were investigated under three sowing schedules; soybean and maize sown together, and maize sown 15 and 30 days after soybean, in addition to soybean and fodder maize sown in pure stands, with maize harvested at green fodder maturity (GFM), and silage maturity (SM). Harvesting fodder maize at SM resulted in higher herbage yield than harvesting it at GFM, yet it negatively affected the soybean productivity. However, this negative impact was offset when fodder maize sowing was delayed 30 days after soybean sowing. Maize harvested at GFM was characterized by a higher leaf component, which was reflected in its higher crude protein content, yet the decline in quality with advanced maturity was to a great extent, counterbalanced by the presence of high-quality ears in maize harvested at SM. This was clear in its lower fiber and higher non-fiber carbohydrate contents. Land equivalent ratio (LER) demonstrated yield advantage with the delayed sowing of fodder maize (LER &gt; 1), while the dry matter equivalent ratio (DMER) associated the yield advantage with the late harvesting of fodder maize at SM (DMER &gt; 1), across all sowing schedules, which was more realistic for an additive intercropping model where the dry matter is the economic component. In a soybean-fodder maize intercropping system, whether fodder maize will be cultivated for green feeding or for silage production, it is recommended that sowing is delayed until 30 days after the soybean, in order to maximize yield advantage and land use efficiency.

OPTIMALISASI USAHATANI SAYUR TUMPANGSARI DI DESA SUKORAMBI KECAMATAN SUKORAMBI KABUPATEN JEMBER

The implementation of intercropping systems is considered by farmers to be able to overcome the problem of low productivity and fluctuations in vegetable prices. The purpose of this study was to determine Combination of intercropping vegetable farming that provides maximum benefits. The determination of the study area was carried out using a purposive method. The sampling technique uses quota sampling. The method of analysis uses linear programming. The results showed that (1) the maximum benefit of the intercropping model 1 was obtained by planting green mustard and spinach, the intercropping model 2 planting green mustard, spinach and kale, the intercropping model 3 planting green mustard, spinach and basil, the intercropping model 4 planting spinach, green mustard, marigolds and basil. (2) Rare production factors are spinach land on intercropping models 1, 2, 3 and 4, basil land on intercropping model 4, ZA fertilizer on intercropping model 1, manure on intercropping models 2, 3 and 4, callicron pesticide on intercropping model 2 and 4 as well as the amnistar top pesticides in intercropping model 3. (3) The highest increase in maximum profit conditions is in the intercropping model 4 by 15.7% and the lowest in the intercropping model 1 by 13.6%.

Determination of raw biomass, yield and income from intercropping models of coffee (Coffea canephora Pierre) compare with perennial trees in tropical climate

This is the first report of evaluation of 4 Robusta coffee intercropping models (Coffea canephora Pierre var. Robusta) with perennial trees (Siamese cassia and durian) on Rhodic ferrasol soil and tropical climate. The models were: T0 - sole coffee, T1 - intercrop of coffee with Siamese cassia (Cassia siamea Lam.), T2 – intercrop of coffee with durian (Durio zibethinus Murr.) at 9 x 9 m distance and T3 – intercrop of coffee with durian at 9 x 6 m distance. The results showed that the raw biomass increased from 71.6 tons ha-1 (T0) to 101.4 tons ha-1 (T1) or to 176.4 tons ha-1 (T2) or to 178.6 tons ha-1 (T3). The yield of dry coffee beans in T2 model was reduced by 300 kg ha-1 and by 1,000 kg ha-1 in T3 model, respectively, compared with T0 (4,120 kg.ha-1). However, they are in the same level with T1 (4,202 kg ha-1). The T2 and T3 models produced 22 and 23 tons ha-1 of durian fruits, respectively. Currently, planting of coffee solely or intercropping with forestry trees are popular methods of growers. We recommend that farmers should intercrop coffee with perennial fruit trees, which creates higher total-income and larger raw biomass.

Effects of intercropping on cadmium uptake by maize and tomato

In order to explore the effect of intercropping on the uptake of heavy metal cadmium (Cd), pot experiments were undertaken using three different planting methods: monoculture, restrictive intercropping and intercropping. The effects of Cd accumulation in different plant parts, and their causes, were examined using a plant species regarded as a relatively high heavy metal accumulator (tomato: Lycopersicon esculentum var. Zhongshu 4) and a species regarded as a relatively low heavy metal accumulator (maize: Zea mays L. var. Jinzhumi). Cd levels for all experiments were 3.70 mg/kg. Results indicate that restricted intercropping and intercropping of tomato and maize increased the accumulation of Cd (from 13.52 mg/kg to 24.94 mg/kg and 27.30 mg/kg in tomato leaf, respectively). Compared with the control group, pH levels in soil surrounding tomato roots in the intercropped samples decreased and the activity of acid phosphatase increased, while the activity of urease decreased. Intercropping can also change the structure of the crop root microorganism population, increase the abundance of microbiological species that promote the uptake of heavy metals, and finally achieve high accumulation of Cd in tomatoes. Our research results provide reference for controlling soil heavy metal pollution and ensuring food safety by using an intercropping model.