Grass Intercropping Research Articles

Effect of Seed Rate on Forage Yield, and Nutritional Value of Sudan Grass and Vetch Mixtures in Ethiopia: A Review

The livestock feed resources in Ethiopia are classified as natural pasture, crop residues, improved pasture and forage, agro-industrial by-products, and also hay production of which the first two feed resources are the major feed contributors for the livestock production in Ethiopia but they are lacking in protein and minerals. Natural pastures contribute about 80-85 of animal feed in Ethiopia, including naturally occurring grasses, legumes, shrubs, hurbs, and tree foliages. Crop residue is one of the feed resources used for animal production in Ethiopia and is available in those areas in which livestock and crop production are practiced. Around 30 million tonnes of DM of agricultural crop residues are produced annually on the national scale, of which 70% are used as animal feed. The major agro-industrial by products commonly used in Ethiopia are obtained from different agro-industries. The nutritional values of agro-industrial by products are excellent but their productivity is small, limited, and limited to few farms in urban and peri-urban areas and they contribute much less to livestock feed. Furthermore, traditional livestock feed supply mainly depends upon natural pasture and crop residues, which have low crude protein and other chemical composition. However, there is tremendous potential to alleviate feed shortages using improved forage production. To fulfill this gap, producing a stable improved forage in the livestock sector is mandatory. For that reason, the legume and grass intercropping system are important to increase biomass production and forage yield. Hence, Sudan grass (Aden gode) known with its plant height than other cultivars and vetch (<i>Vicia dasycarpa</i>) have greater plant height and creeping growth habit that enable compatible to larger grass species and they are selectable forages to enhance the forage yield and quality under similar times.

Effect of Spacing of Elephant Grass Intercropping with Alfalfa on Biomass Yield and Nutritive Value of Elephant Grass in Fedis District, Eastern Ethiopia

The study was conducted by Fedis Agricultural Research Center (FARC) at Boko station in Fedis district. The experiment consisted of three different spacing arrangements: S1 (100 cm x 50 cm), S2 (75 cm x 50cm) and S3 (50 cm x 50 cm), and two cropping systems (intercrop and sole planting). These treatments were combined in a 3 x 2 factorial arrangement using a randomized complete block design with four replications. Forage samples were collected at ninety (90) days for elephant grass and 10% flowering for Alfalfa. The results showed that spacing and the interaction between spacing and intercropping had a significant (p<0.05) effect on herbage dry matter yield (DMY) and crude protein yield (CPY) of elephant grass. However, intercropping had no significant (p>0.05) effect on herbage DMY and CPY. Intercropping can increase the yield of herbage dry matter and total herbage dry matter when compared to pure stand elephant grass. The yield advantage can be up to 3.18% and 19.65%, respectively. Spacing does not significantly affect the dry matter yield of Alfalfa, but the cropping system does. Intercropping and narrow spacing resulted in higher total dry matter yield, due to the additive effect of intercropped Alfalfa dry matter yield. Among the three different spacing, the narrowest spacing S3 recorded the highest dry matter yield (25.62 t/ha), followed by S2 (22.28 t/ha) and S1 (18.33 t/ha). Spacing and intercropping have no significant effect on the chemical composition of elephant grass, but intercropping can increase the dry matter and decrease the ash content of elephant grass. Farmers in the study area and other regions with similar agro-ecology are advised to consider intercropping Alfalfa two weeks after establishing elephant grass. This should be done at an inter and intra-row spacing of 50 cm to achieve a higher herbage dry matter yield for both, elephant grass and total forage.

Viabilidade econômica de um sistema silvipastoril com e sem a inclusão de crédito de carbono

ABSTRACT This study analyzes the economic viability of exotic and native caatinga forest species grown in silvopastoral systems, combined with the Guinea grass forage crop, compared to monoculture forestry systems, using carbon credits as an alternative source of extra income, aiming for an economic return on the sale of standing timber for firewood production. The experiment was conducted at the Experimental Station of the Pernambuco Agricultural Research Institute (IPA) in Belém do São Francisco, located in the semi-arid region of the state of Pernambuco, in the Itaparica micro region. Four tree crops were chosen, two of which are native to the Caatinga biome: Angico (Anadenanthera colubrina var. Cebil) and Aroeira (Myracrodruon urundeuva Allemão), and two exotic eucalyptus clones, E. urophylla x E. tereticornis. Guinea grass (Panicum maximum Jacq) was chosen as the forage. The intercropping of Guinea grass with the two eucalyptus clones proved to be economically viable in all the economic parameters analyzed, and this is the most suitable for marketing standing wood for firewood production. It is not economically advisable to sell the standing wood for firewood production in the monoculture and silvopastoral systems with the native species (Angico and Aroeira) at 96 months of age due to the system's economic unfeasibility. By adding the possibility of financial credit through the atmospheric carbon sequestered by the trees, it is possible to make all the costs of forestry crops in silvopastoral and monoculture systems economically viable.

Sistema de consórcio de milho com gramíneas forrageiras e o uso de doses reduzidas do herbicida mesotrione

ABSTRACT Sowing forage grass species of the genera Urochloa and Panicum simultaneously with corn can hinder crop grain yield, requiring the application of low herbicide rates for suppressing their growth and preventing potential competition with corn plants. Therefore, the objective of this study was to evaluate the use of low rates of the herbicide mesotrione for inhibiting the growth of forage grass species (Urochloa ruziziensis and Panicum maximum, cultivars BRS Tamani and BRS Zuri) sown simultaneously with corn crop, as well as the recovery capacity of these grasses. Two experiments were installed, as first and second crop seasons, in a randomized experimental block design with four replications, using a 3×4 factorial arrangement and three control treatments with corn alone. Each of the three forage grasses was sown simultaneously with corn and subjected to post-emergence application of four mesotrione rates (0, 48, 96, and 144 g ha-1) with atrazine (1.25 kg ha-1). Weeds, forage grasses, and corn plants were evaluated. BRS Tamani was the most tolerant forage to mesotrione, while BRS Zuri was the most sensitive. The application of mesotrione + atrazine in the corn-forage grass intercropping system contributed to weed control. The tested forage grasses did not affect corn grain yield in the first or second crop season, even with no herbicide application.

Maize-Brachiaria grass intercropping: A meta-analysis of major productivity drivers in Brazil

Context or problemIncreasing crop intensification while enhancing soil conservation is an important aspect of global food security. Intercropping (syn. interseeding) between cash crops and tropical forages improves soil cover, prevents soil erosion, and enhances land use via crop and livestock integration. In Brazil, intercropping between maize (Zea mays L.) and Brachiaria grass (Urochloa spp.) is the most commonly adopted system, with opportunities for expansion across tropical and subtropical landscapes worldwide. Nonetheless, there is little consensus on the effects of intercropping on the performance of each individual crop species. Objective or research questionA meta-analysis was conducted to quantify the effect of intercropping on maize grain yield and Brachiaria grass biomass production and to understand the impact of environmental and management factors on intercropping performance. MethodsA literature search was conducted to retrieve peer-reviewed studies carried out on this intercropping system under field conditions. Manuscripts were scrutinized and included in this meta-analysis when they met the following criteria: i) data on maize grain yield and Brachiaria grass biomass under intercropping were reported, ii) inclusion of a control treatment (monocropping) for at least one species, and iii) field trials with at least three randomized replications. Our database included 429 data points extracted from 56 published manuscripts from all regions of Brazil. ResultsRelative to monocropping, intercropping reduced maize grain yield (−5.6 %) and Brachiaria grass biomass production (−64 %) in all scenarios. The intercropped maize grain yield was less affected under the following conditions: i) in the subtropical climate zone (−3.6 %), ii) sowing the intercrop early in the season (−5.8 %), iii) applying monocot-selective postemergence herbicides (−4.4 %), iv) relay temporal arrangement (−2.8 %), and v) with N and P fertilization rates above 150 and 35 kg ha-1, respectively. In relative terms, Brachiaria grass performance was more affected by i) intercropping adoption, with a reduced biomass penalty under a tropical climate (−63.9 %), ii) late sowing time for the intercrop (−59.5 %), iii) application of N fertilizer at a rate above 50 kg ha-1 (−70.5 %), and iv) non-use of postemergence herbicides (−21.9 %). ConclusionMaize-Brachiaria grass intercropping was an effective alternative to produce residue (no-till system adoption) or forage (crop-livestock integrated system adoption) with reduced maize grain yield penalties, diversifying cropping systems in Brazil. Implications or significanceDespite the production penalties for both crop species, considering different relative values, specific management practices and climate conditions could minimize yield penalties. Scenarios favoring maize yields may be preferred for intercropping systems focused on improving soil quality; in contrast, Brachiaria grass biomass may benefit the integration of crop-livestock systems focused on ensuring forage production.

Potential interaction of soybean-grass intercropping with residual nitrogen for a no-tillage system implementation

Combinations between crop intercropping and forage production in a no-tillage system are not well established for environments under low water retention and soil fertility conditions. Our study aimed to evaluate the potential interactions between soybean-grass intercropping with residual nitrogen in a no-tillage system. The experimental design was a randomized block with four replications in a subdivided plot scheme. The main plots in the summer season were: 1) soybean monoculture; 2) soybean - Aruana Guinea grass (Megathyrsus maximus cv. Aruana) intercropping, and 3) soybean - Congo grass (Urochloa ruziziensis cv. Comum) intercropping. The subplots were the nitrogen rates of 0, 50, 100, and 150 kg ha-1, applied as side-dressing in maize and grasses during the autumn-winter season. Here, the results of the summer seasons are shown. To do so, the parameters evaluated were soybean agronomic traits, dry biomass production, and macronutrient concentrations of plants intercropped. The main effects and interactions were studied. Our findings showed that soybean-Aruana Guinea grass intercropping is an alternative to no-tillage system implementation. Moreover, residual nitrogen from the autumn-winter season directly interfered with the dry biomass production of grasses intercropped with soybeans in the summer season. In short, the systems studied seem suitable for implementing a no-tillage system, which aims to neutralize degraded pastures and produce forage for ensilage. Despite the changes in macronutrient concentrations within the intercropping system and residual nitrogen, and among intercropped crops over the years, Congo grass intercropped with soybeans in the summer season showed great capacity for phosphorus, potassium, and magnesium cycling.

Soybean Yield and Nutrition Grown on the Straw of Grain Sorghum Inoculated with Azospirillum brasilense and Intercropped with BRS Paiaguás Grass.

The adoption of diversified agricultural systems that employ integrated cultural practices appears to be the way to sustainably intensify tropical agriculture. Our objectives were to evaluate the dry matter (DM) accumulation of sorghum inoculated with Azospirillum brasilense, with or without a nitrogen fertilization split, intercropped with palisade grass (Urochloa brizantha cv. BRS Paiaguás), and how these practices influenced the nutrition and development of soybean in succession. The design was a randomized complete block in a 2 × 2 × 3 factorial, consisting of sorghum monoculture cropped or intercropped with palisade grass, sorghum either inoculated or not with A. brasilense, and nitrogen applied at 120 kg ha-1 N only at sowing, only at topdressing, or split-30% at sowing and 70% at topdressing at the beginning of the panicle initiation stage. The residual impacts of these treatments on the following soybean crop were also evaluated. Higher DM yield occurred in sorghum inoculated with A. brasilense, however, this result varied by year. The sorghum-palisade grass intercrop produced a higher amount of straw than sorghum monoculture. The nutrition of soybean was adequate regardless of treatments, but grain yield was higher when the sorghum residue was inoculated. The inoculation of A. brasilense in sorghum intercropped with palisade grass increased yield. The nutrition of soybean was adequate regardless of the treatments, while grain yield was higher on the inoculated sorghum residues. The inoculation of A. brasilense in sorghum intercropped with palisade grass increased DM yield. The intercropping increased the production of biomass for animal grazing and DM for soil coverage. The inoculation of sorghum by A. brasilense and its intercropping with palisade grass contributed to higher soybean yield in succession.

Impact of intercropping grass on the soil rhizosphere microbial community and soil ecosystem function in a walnut orchard.

The intercropping of grass in orchards has beneficial effects on soil properties and soil microbial communities and is an important soil management measure for improving orchard productivity and land-use efficiency. However, few studies have explored the effects of grass intercropping on rhizosphere microorganisms in walnut orchards. In this study, we explored the microbial communities of clear tillage (CT), walnut/ryegrass (Lolium perenne L.) (Lp), and walnut/hairy vetch (Vicia villosa Roth.) (Vv) intercropping system using MiSeq sequencing and metagenomic sequencing. The results revealed that the composition and structure of the soil bacterial community changed significantly with walnut/Vv intercropping compared to CT and walnut/Lp intercropping. Moreover, the walnut/hairy vetch intercropping system had the most complex connections between bacterial taxa. In addition, we found that the soil microorganisms of walnut/Vv intercropping had a higher potential for nitrogen cycling and carbohydrate metabolism, which may be related to the functions of Burkholderia, Rhodopseudomonas, Pseudomonas, Agrobacterium, Paraburkholderia, and Flavobacterium. Overall, this study provided a theoretical basis for understanding the microbial communities associated with grass intercropping in walnut orchards, providing better guidance for the management of walnut orchards.

Is the Integration between Corn and Grass under Different Sowing Modalities a Viable Alternative for Silage?

This study aimed to evaluate the fermentation pattern and dry-matter losses in corn (Zea mays L.) silage intercropped with Urochloa brizantha cv. Marandu and Megathyrsus maximus cv. Mombasa grasses in different sowing modalities through crop-livestock integration. The experimental design was in randomized blocks, which were arranged in a 2 × 5 factorial scheme with four repetitions. The first factor consisted of the grass cultivars Marandu and Mombasa. The second factor was the sowing modalities of grasses intercropped with corn: (1) simultaneous row sowing and inter-row corn sowing (no fertilizer); (2) simultaneous row sowing and inter-row corn sowing (with fertilizer); (3) simultaneous sowing with double grass row in the corn inter-row; (4) delayed sowing inter-row at 7 days after corn emergence; and (5) delayed sowing inter-row at 14 days after corn emergence. The forage buffer capacity (BC), silage pH and ammoniacal nitrogen (NH3-N) content, forage (FORDM) and silage dry-matter (SILDM) percentages, gas losses (GL), effluent losses (EL), and dry-matter recovery (DMR) parameters on the ensilage were evaluated. Only forage BC, silage NH3-N, and silage DMR variables differed (p < 0.05) from the control silage (monocropped corn) when the integration was carried out. The grass cultivar factors and sowing modalities for BC and NH3-N variables had an effect. The intercropping of corn and Marandu grass or Mombasa grass, in any grass sowing modality, did not affect the quality of the silage.

Sorghum–Grass Intercropping Systems under Varying Planting Densities in a Semi-Arid Region: Focusing on Soil Carbon and Grain Yield in the Conservation Systems

A major challenge in sorghum intercropping systems is maintaining their yields compared to the yields of the solo crops, especially in arid and semi-arid regions. This study aimed to test the hypothesis that intercropping systems using sorghum (Sorghum bicolor (L.) Moench.) and Brachiaria sp. are viable means to increase sorghum production and soil carbon in the conservation systems. Field trials were conducted in the semi-arid region of Minas Gerais, Brazil, during two crop cycles of sorghum associated with different grasses (Andropogon gayanus—AG; Cenchrus ciliaris cv. Aridus—CCA; Cenchrus ciliaris cv. 131—CC; Brachiaria decumbents—BD; Brachiaria brizantha—BB; Brachiaria ruziziensis—BR; Panicum maximum—PM), using row spacings of 0.4 and 0.8 m. Panicles of sorghum (yield) and grass dry matter were collected to determine yields. Results showed that the addition of grasses in systems decreased the grain yield in all systems, except in the systems using sorghum with CCA in 0.4 m, AG in 0.8 m, or BR in 0.8 m. In the 0.4 m row spacing, the sorghum associations with CC, BB, or PM are greater alternatives to increase soil carbon. However, when the row spacing was increased, the sole sorghum was the best alternative to increase the carbon. In machine learning, sorghum systems with CCA and AG are better alternatives to increase the yields, while sorghum with CC, PM, BR, and BB increases the grass dry matter in soil.

Improving Fodder Yields and Nutritive Value of Some Forage Grasses as Animal Feeds through Intercropping with Egyptian Clover (Trifolium alexandrinum L.)

The present study aimed to evaluate the potential of improving the feeding value of Egyptian clover (EC), ryegrass (R), triticale (T), barley (B), and oats (O) monoculture, or Egyptian clover mixed with ryegrass (EC+R), oats (EC+O), barely (EC+B), and triticale (EC+T) at 75:25% seeding rate, respectively, during two successive winter seasons of 2018/19 and 2019/20. Harvesting of plots was carried out at 5 cm stubble height after 60, 100, and 140 days from sowing. The in vitro nutritive value and ruminal fermentation of the monoculture and intercropping containing EC were evaluated. Green forage yield of EC was higher than other plants with about 160% of fresh forage compared with T, O, or EC+T intercropping. The highest crude protein (CP) concentration was noted in EC, while the lowest (p &lt; 0.001) concentration was observed in T, which had the highest fiber fractions content. Ryegrass had the highest net in vitro gas production (GP), while EC+R had the lowest GP (p &lt; 0.05). The EC increased dry matter and organic matter degradability. EC and R reduced protozoal count, while total volatile fatty acids (VFA), acetate, and propionate were increased with B and EC+T intercropping (p &lt; 0.05). Overall, intercropping of EC with grass of triticale or ryegrass at mixing rates of 75:25% resulted in improving fresh and dry forage yields. The legume–grass intercropping improved the protozoa count partitioning factor as an index of microbial protein synthesis and total VFA concentration.

Effects of water levels on plant traits and nitrogen use efficiency in monoculture and intercropped artificial grasslands.

Water availability is the main factor affecting the forage productivity of artificial grasslands, particularly in semi-arid regions. Generally, intercropping of gramineous grass and leguminous grass can achieve high productivity. However, how different water availability levels affect the productivity of intercropping system remains unclear. Here, we conducted a 3-year (2015–2017) study by manipulating the water conditions (CK equivalent to the annual precipitation, +50% treatment equivalent to 50% increase over the average precipitation, and −50% treatment equivalent to 50% decrease over the average precipitation) to explore the responses of plant traits, nitrogen use efficiency, and biomass of the monoculture of Medicago sativa (a leguminous grass, M.s), monoculture of Elymus nutans (a gramineous grass, E.n), and intercropping of M.s and E.n in a semi-arid region in Inner Mongolia, China. The results showed that the biomass obtained by intercropping of M.s and E.n decreased by 24.4% in −50% treatment compared to the CK treatment, while that of the monoculture of M.s decreased by 34.4% under the −50% treatment compared to the CK treatment. However, there was no significant difference in the biomass between intercropping artificial grassland and monoculture M. sativa under +50% treatment. Compared to monoculture, M.s can obtain more nitrogen by biological nitrogen fixation and decrease the proportion of nitrogen absorbed from soils under intercropping in the same water conditions. Under the intercropping system, the proportions of nitrogen absorbed from soils by M.s were 87.4%, 85.1, and 76.9% in −50%, CK, and +50% treatments, respectively. Under monoculture, these proportions were 91.9, 89.3, and 82.3% in −50%, CK, and +50% treatments, respectively. Plant trait, but not soil nitrogen content, was the main regulator for the productivity responses to water level changes. Our results highlight that intercropping can achieve higher productivity in both dry and wet conditions. Therefore, considering the fluctuating rainfall events in the future, it might be useful to alter the proportions of intercropped forage species in an artificial grassland to obtain optimal productivity by reducing the limitations of nitrogen availability. However, the economic viability of intercropping M. sativa and E. nutans should be evaluated in the future.

Nitrogen fertilization strategies with protected urea for tropical grasses in an integrated crop-livestock system

The intercropping of corn and grass allows for the production of grains, and simultaneously, the recuperation and renovation of pastures. This study aimed to evaluate the effects of N doses on the yield, structure, chemical-bromatological characteristics, and the N use efficiency of Brachiara brizantha cultivars in an integrated crop-livestock system. The experimental design was completely randomized, with four replications, in a slip-plot scheme. The plots were formed of two grass plants, Marandu and Paiaguás, intercropped with corn and subplots composed of nitrogen doses (70, 100, and 130 kg N ha-1). During the system’s establishment (1st cycle), the Paiaguás grass presented higher values for all morphogenic and structural characteristics and higher forage yield when compared to Marandu grass. After the corn harvest, the interaction effect of the N doses and the cultivars for the foliar structure emergence and the number of living leaves was observed. The variables foliar elongation rate, stem elongation rate, and phyllochron were not influenced by any of the investigated factors (P&gt;0.05). The highest DM content was obtained with the application of 100 kg ha-1 of N, whereas, for the other chemical characteristics, there was only an effect among the cultivars. Paiaguás grass exhibited the highest levels of NDF, ADF, lignin, and MM. CP levels were not influenced by the factors studied. Marandu grass and the use of 70 kg N ha-1 are recommended for intercropping with corn

Viability of a macauba palm–Brachiaria grass intercropping system as an alternative to agroforestry production

In intercropping systems, shading is one of the main limiting factors for the development of plants in the understory, especially C4 plants. However, successful pasture production in silvopastoral systems can be achieved through proper spatial arrangement. This study provides fundamental information that validates the macauba-grass consortium. For 20 months, during two dry seasons and two rainy seasons, microclimatic and physical variables in an Acrocomia aculeata–Brachiaria decumbens intercropping system were monitored. The spacings of the trees were 5 m × 4 m, 6 m × 4 m, 7 m × 4 m, and 8 m × 4 m and were compared to a traditional pasture. The aboveground biomass in the intercropping system was estimated as well as its ability to assimilate atmospheric CO2 and store carbon. Macauba palm presence in the intercropping system had a regulatory effect on the microclimatic conditions of the understory, regardless of tree spacing and season. In spacing, wider, the intercropped forage biomass was satisfactory and similar to that in the monocrop pastures. The spacing 7 m × 4 m and 8 m × 4 m improved the understory microclimatic conditions, allowing efficient forage growth and thus offering livestock food and comfort. These values were equivalent to those of traditional silvopastoral systems that use woody plant species. The estimates of aboveground biomass, carbon stock, and CO2 assimilation in the intercropping system with a spacing of 8 m × 4 m were 1.6 times greater than those of traditional pastures. Therefore, here, we show for the first time that A. aculeata–B. decumbens grass intercropping system is a viable alternative agroforestry practice for tropical regions, since sufficient amounts of fodder are provided alongside beneficial environmental services, such as the efficient sequestration and storage of atmospheric carbon.

Changes in soil profile hydraulic properties and porosity as affected by deep tillage soil preparation and Brachiaria grass intercropping in a recent coffee plantation on a naturally dense Inceptisol

Soil management operations change soil porosity, affecting water infiltration, redistribution, storage, availability, and uptake by plants. Assessing how soil management may affect pore size distribution and hydraulic conductivity is thus highly relevant for rainfed agriculture coping with water shortage. The aim of this study was to assess the effectiveness of tillage treatments, designed to deepen coffee plants root system, on improving structure and physical-hydric attributes of an Inceptisol with a shallow solum. The study was conducted in an experimental area in the municipality of Nazareno, Minas Gerais State, Brazil. Soil samples were collected 18 months after coffee plantation, at different depths (0, 0.25, 0.35, 0.45, 0.55, 0.66, and 0.75 m) and they were used to determine pore-size distribution, saturated and unsaturated hydraulic conductivity. Samples were also collected in surface crusts or in the 0−0.005 m soil layer for detailed grain size analysis. Field water infiltration was measured at different water tensions. Coffee seedlings were planted in rows furrowed to depths depending on tillage treatment: 0.4 m depth, made by a furrow ridger (FP40); 0.6 m depth, made by a subsoiler coupled to a soil preparer mixing the soil to a depth of 0.6 m (FP60); 0.8 m depth, made by a subsoiler and, after mixing the soil to a depth of 0.6 m, by the soil preparer (FP80). The soil between the planting rows was covered by Brachiaria-grass. Soil sampling and field tests were performed in the coffee plants row mechanically treated, in the Brachiaria-grassed inter-row (IR) lane and in a nearby area under natural vegetation (NC). Treatments effects, either mechanical in the coffee rows (FP40, FP 60 and FP80), or biological in the inter-row lane (IR) were compared to reference (NC), representing soil conditions prior to coffee plantation. The FP60 and FP80 treatments improved water infiltration, storage and hydraulic conductivity in the planting rows to a depth of 0.5 m. A more favorable pore size distribution was obtained following these treatments, which improved the soil physical environment. Conversely, furrowing promoted compaction at each implement working depth due to the pressure applied by the rods in the subsurface soil layers, combined with subsoil moisture condition at the time of operations. Root activity of intercropped Brachiaria-grass (IR) improved soil structure, expressed by a favorable pore-size distribution and a faster hydraulic conductivity in the inter-row lane. Similar effects were obtained with FP 60 and FP80 for the coffee rows, where deep furrowing during soil preparation reduced the natural density of the Inceptisol. Therefore, the management strategies tested allowed root deepening and access to soil moisture stored in deeper layers.

Effects of Crop and Grass Intercropping on the Soil Environment in the Karst Area

The karst area in Southwest China is facing the challenges of environmental degradation and agricultural safety. Intercropping is a green and efficient planting mode that can make full use of the differences in crops’ physiological and ecological characteristics and land and climate resources while considering the environmental and yield benefits. This study selected five treatments: Salvia miltiorrhiza monoculture, Dactylis glomerata intercropped with S. miltiorrhiza, Cichorium intybus intercropped with S.miltiorrhiza, Trifolium repens intercropped with S.miltiorrhiza, and Lolium perenne intercropped with S.miltiorrhiza. Using one-way ANOVA, principle component analysis (PCA), and linear correlation analysis, we analyzed the changes in the soil physicochemical factors and the coupling relationship between them in the intercropping mode. The results showed that at different soil depths, the soil bulk density in the intercropping mode was significantly lower than that in the single cropping mode (p &lt; 0.05), and the soil water content and total porosity were significantly increased (p &lt; 0.05). There were no significant differences in soil pH among the five models (p &gt; 0.05), the content of soil organic matter was significantly higher than that in the single cropping mode (p &lt; 0.05), and the content of nitrogen and phosphorus also showed different changes. The correlation analysis showed that there was no significant correlation between the pH and soil physical properties (p &gt; 0.05); bulk density and chemical properties were negatively correlated, while the soil water content, field water-holding capacity, and total porosity were significantly positively correlated with the chemical properties (p &gt; 0.05). Therefore, it is suggested to strengthen the management of agricultural grass intercropping, improve soil pore structure, regulate the distribution of soil water and fertilizer, and improve the resilience of agricultural systems in the karst area of southwest China.

Nutritional Regime of the Soil and Growth Activity of the Apple Tree Root System in Orchards with Legume-Cereal Grass Intercropping

This work aims to study the influence of legume-cereal grasses in the inter-row spacings of the garden on the content of nutrients in the soil and the growth of apple tree roots. The amount of nitrate nitrogen was in direct proportion to the ratio of the legume component in the phytocenosis. The nitrogen content in the control option was the smallest: 19.7 mg/kg in the soil layer of 0-30 cm and 13.4 mg/kg in the layer of 30-60 cm. In the case of natural grassing-down between rows, cereal forbs prevailed. The largest amount of nitrate nitrogen was achieved when sowing the red clover and timothy grass in a ratio of 7:3. The accumulation of nitrate nitrogen is due to the activity of nodule bacteria on the roots of red clover. The accumulation of mobile phosphorus and exchangeable potassium depends on the amount of mowed mass in the inter-row spacings of the garden. The lowest content of mobile phosphorus was detected for natural grassing. In the control option, its amount was 118 mg/kg. In the 0-30 cm soil layer, the content of mobile phosphorus was 127.4-142.6 mg/kg depending on the ratio of legume-cereal grasses, and it amounted to 95.1-103.2 mg/kg in the 30-60 cm layer. For the ratio of red clover and timothy grass 3:7, the highest phosphorus content was detected. The intercropping of the garden with a legume-cereal herbal mixture also contributed to a greater accumulation of exchangeable potassium in the soil relative to natural grassing-down - 122.3-134.9 mg/kg. The optimal ratio of legume-cereal component was 3:7. A higher growth activity of the roots of the apple tree was noted in the option with sodding with a mixture of red clover and timothy grass in a ratio of 7:3.

Silage of Intercropping Corn, Palisade Grass, and Pigeon Pea Increases Protein Content and Reduces In Vitro Methane Production

Legume–grass intercropping systems are a sustainable option to improve nutritional quality of animal feed and decrease livestock greenhouse gas emissions. Thus, the present study evaluated yield, chemical composition and in vitro gas production of silages produced with intercropped palisade grass (Urochloa brizantha.(A.Rich.) R.D.Webster), pigeon pea (Cajanus cajan cv. Super N) and corn (Zea mays. L.). Forage was harvested and placed inside micro-silos, which were opened after 100 days and samples were collected for chemical composition and in vitro gas production analyses. Intercropped silage had higher crude protein, acid detergent fiber, and lignin content than corn silage. Moreover, intercropped silage decreased total gas and methane production. Therefore, intercropped silage showed potential to increase conserved feed nutritional quality and reduce methane emissions in livestock production systems.

Optimizing Cropping Systems of Cultivated Pastures in the Mountain–Basin Systems in Northwest China

Cultivated pastures are effective supporting systems of natural grassland preservation and sustainable agriculture in arid regions of northwest China. The adaptive combination of forage species enhances the yields and ecological functions of cultivated pastures. Legume–grass intercropping is a valuable sowing regime because of the niche differentiation and resource acquisition. Understanding the effects of species interactions in legume–grass intercropping systems can provide scientific and practical guidance on cultivated pasture management. In this study, we conducted a field experiment to determine the advantages and effects of alfalfa (Medicago sativa L.) annual grass intercropping on cultivated pastures. We analyzed the data on population traits, community characteristics and dry matter in the growing period to evaluate the effects of variety and sowing patterns with the following treatments: three alfalfa varieties (Algonquin, Leafy king, WL354HQ) sown in monocultures and mixed with oat (Avena sativa L.) or sudangrass (Sorghum sudanense (Piper) Stapf.) with two seeding ratios. Our results suggest that in mixtures, the plant traits of alfalfa were determined by their own characters at the earlier stage but were affected more by companion grass at the later stage. The annual forage grass companion impaired the growth of alfalfa during the growth period. In mixtures, sudangrass displayed a stronger inhibiting effect on alfalfa than oat. Alfalfa–grass intercropping was proved to be a feasible cropping practice in terms of yield, production stability and weed control, due to their complementary use of resources in comparison with alfalfa monocropping. Alfalfa–annual grass intercropping is a beneficial alternative strategy to obtain effective cultivated pastures in arid regions.

No-tillage and crop rotation increase crop yields and nitrogen stocks in sandy soils under agroclimatic risk

Agricultural production is challenging in environments with climatic instability, high temperatures, and water deficits, particularly in sandy soils. The use of no-tillage, crop rotation, and cover crops can increase the sustainability of cropping systems under these conditions. Nitrogen (N) is important to improve carbon production and soil organic matter. The objective of this study was to evaluate the effect of summer crop rotation (sorghum or soybean), tillage system (no-tillage and conventional), and intercropping (maize and palisade grass) on crop yield (soybean and maize grain, sorghum silage and palisade grass dry matter) and soil nitrogen stocks. No-tillage system (NT) resulted in yields 6% higher for soybean, 100 % higher for sorghum and 17 % higher for maize, when compared to conventional tillage, and had no effect on palisade yield. The high palisade grass yield after soybean in 2014 decreased soil inorganic N stocks in the 0−60 cm layer, but total soil N was higher when using soybean rotation under NT and after intercropped maize in 2015. Soybean increased maize yields by 25 % (0.86 Mg ha−1) and palisade yields by 46 % (1.5 Mg ha−1) when compared to silage sorghum. Palisade grass decreased maize yield by 30 % with intercropping. Soybean grown under NT after maize and palisade grass intercrop improves soil N stocks and crop yields. Despite palisade grass competition decreasing maize yields in years with rainfall above the historical mean, its use is important to improve soil organic matter over time.