Search

Background and Aims: The intercropping has great advantages in production gain, resources use and soil quality improvement. However, the effects of perennial forage legumes intercropped with annual grain crop on soil alkali-salinity was not well revealed. This study aimed to propose a spring wheat (Triticum aestivum L.)/alfalfa (Medicago sativa L.) intercropping and reveal whether this cropping system could ameliorate soil salinity. Methods: A two-year field experiment was conducted under 3 cropping systems at 3 irrigation amounts in the inland arid area of northwestern China. The cropping systems were sole spring wheat cropping (W), 12 rows spring wheat/4 rows alfalfa intercropping (W12A4) and 8 rows spring wheat/4 rows alfalfa intercropping (W8A4), and irrigation amounts included 450 (full irrigation amount, If), 360 (moderate irrigation amount, Im) and 180 mm (low irrigation amount, Il). Results: The intercropping system, especially W8A4, could more decrease soil salinity, pH and topsoil bulk density, and increase soil water content, topsoil porosity, and Ca2+ and Mg2+ contents, compared to W. Soil electrical conductivity was positively correlated with topsoil bulk density and negatively correlated with topsoil porosity, which were enhanced by intercropping and irrigation. There was weak correlation between soil electrical conductivity and soil water content. W12A4 and W8A4 led to reduction in contents of Na+, K+, Cl−, and SO42−, while Ca2+ and Mg2+ accumulated in the soil. Conclusion: Intercropped alfalfa and spring wheat could reduce soil salinity, improve soil structure and ions balance. It was recommended that W8A4 with 360 mm irrigation could be extensively used in the arid area of northwestern China, gaining grain and forage production, and helping reduce salt accumulation. [ABSTRACT FROM AUTHOR]

Establishing lucerne (Medicago sativa) in dryland conditions poses challenges due to unpredictable rainy seasons and seedling vulnerability. A potential solution is adopting a nurse crop during the first year in the same field. This study aimed to assess the impact of wheat as a nurse crop and crop residue on lucerne establishment in South Africa's Mediterranean climate region. The experiment employed a split-plot design with two treatment factors across six blocks. Half of the area received wheat straw, while the rest had low residue content with almost bare soil. The nurse crop combinations included wheat alone, lucerne alone, and a wheat-lucerne mixture. Results revealed competition between wheat and lucerne when planted together. When plant populations, total biomass, wheat grain yield and grain quality were considered, wheat performed better in pure stands, as did lucerne when grown without wheat. Germination of lucerne was significantly impacted by high crop residue levels. Wheat achieved superior grain yield without crop residue, despite producing less biomass. Results indicated that it is advisable to avoid using a nurse cropping system for lucerne in this Mediterranean climate region. [ABSTRACT FROM AUTHOR]

Under the pressures of global climate change and human activities, the carrying capacity of water and soil resources in agricultural lands has decreased, and the traditional models of agricultural development are no longer sustainable. Land degradation, groundwater quality reduction and ecosystem instability are the consequences of agricultural development without considering sustainability indicators. This article aims to investigate the use of variable relationship analysis and Bayesian network methods to analyze and investigate the relationship between irrigation in agriculture and the sustainability of the groundwater ecosystem. Descriptive statistics of agriculture including cultivation pattern, time, precipitation, irrigation, and land slope were analyzed and combined with the simulated characteristics of groundwater including specific yield, hydraulic conductivity and hydrodynamic diffusion coefficients. Five crops of wheat, barley, paddy, alfalfa, and potato were studied to evaluate the effect of plants on the pattern of nitrate release due to irrigation and fertilization in agriculture. The results showed that managing the amount of fertilizer and the volume of irrigation can positively affect the nitrate distribution pattern in the groundwater even in a short period of time. HIGHLIGHTS The relationships between variables are used to build a logical model for analysis.; The quantity and quality of irrigation water is incorporated into the system for estimating the nitrate concentration in groundwater.;

Cultivated grasslands are an important part of grassland ecosystems and have been proven to be major carbon sinks, then playing an important role in the global carbon balance. The effect of cultivated grassland type (Medicago sativa, Triticum aestivum, Secale cereale, and Vicia villosa grasslands) on carbon flux (including net ecosystem CO2 exchange (NEE), ecosystem respiration (ER), and gross ecosystem productivity (GEP)) downstream of the Yellow River was studied via the static chamber technique and a portable photosynthetic system. Bare land was used as a control. The results showed that the four cultivated grassland types were mainly carbon sinks, and bare land was a carbon source. The cultivated grassland types significantly affected carbon flux. The average NEE and GEP of the grassland types were in the following order from high to low: Medicago sativa, Secale cereale, Triticum aestivum, and Vicia villosa grassland. Stepwise regression analysis showed that among all measured environmental factors, soil pH, soil bulk density (BD), soil organic carbon (SOC), and soil microbial carbon (MBC) were the main factors affecting CO2 flux. The combined influence of soil BD, SOC, and pH accounted for 77.6% of the variations in NEE, while soil BD, SOC, and MBC collectively explained 79.8% of changes in ER and 72.9% of the changes in GEP. This finding indicates that Medicago sativa grassland is a cultivated grassland with a high carbon sink level. The changes in carbon flux were dominated by the effects of soil physicochemical properties. [ABSTRACT FROM AUTHOR]

This study evaluates UVC light as an alternative to improve the microbiological quality of seeds intended for sprouting. UVC treatments with light exposure times up to 120 and 180 min were tested to reduce native bacterial population (NBP) in alfalfa, wheat, and chia seeds. The effects of the UVC light treatments on germination yield and rate, growth kinetics and antioxidant activity of sprouts were also evaluated. Results demonstrated that reductions of NBP after 180 min of UVC light exposure were dependent on the type of seed and their physical characteristics. The Weibull model demonstrated good fitness to experimental data (R2 >0.96) for the concave upward inactivation kinetics (n <1). Besides, the tested UVC light treatments did not affect the germination yield of the studied seeds and decreased the germination time to attain the commercial height of alfalfa and chia sprouts. The UVC light treatments applied on the studied seeds influenced positively the antioxidant properties when sprouting. The application of UVC light to alfalfa and wheat seeds destined for sprouting might be an alternative to improve their microbiological quality of seeds, without affecting their germination properties; while the nutritional benefits of its application, primordially focused to enhance its antioxidant properties of sprouts can be considered for chia and alfalfa seeds. • Effective inactivation of native microbiota of alfalfa and wheat seeds by UVC light. • UVC light treatments improves germination rate of alfalfa and chia seeds. • Antioxidant activity is enhanced by UVC light treatments of seeds when sprouting. [ABSTRACT FROM AUTHOR]

Intercropping pasture with grain crops provides a strategy for diversifying cropping systems and establishing a foundation for mixed crop-livestock farming systems. Investigating the effects of strip design and nitrogen (N) application on interspecific interaction, crop yield, N use efficiency (NUE), and land equivalent ratio (LER) in dryland wheat/alfalfa intercropping. We conducted a four-year field experiment, which tested three intercrops, namely, 2-row wheat with 1-row alfalfa (I21), 4-row wheat with 2-row alfalfa (I42), and 8-row wheat with 4-row alfalfa (I84), as well as sole wheat (SW) and alfalfa (SA). N rates of 150 (HN) and 75 kg ha−1 (LN) were applied for wheat. Winter wheat exhibited earlier spring green-up than alfalfa and maintained dominance during co-growth. Over the four seasons, I21, I42, and I84 resulted in wheat yield (based on the wheat strip area) increases of 19.0%, 16.7%, and 24.0%, respectively, under HN, and 34.1%, 31.9%, and 43.4% under LN. Alfalfa growth was constrained during co-growth but recovered after the wheat harvest. Alfalfa in I42 and I84 maintained forage yield (based on the alfalfa strip area) as high as SA. Intercropping increased wheat NUE under both N conditions but did not significantly affect alfalfa NUE. I84 attained the highest LER of 1.01–1.14 and 1.11–1.25 under HN and LN respectively. Net revenue of I84 was lower than SA but three times higher than SW. Wide-strip wheat/alfalfa intercrop with low-N showed the best performance, which is promising in diversifying farming system and improving agricultural sustainability. • Wheat yield improvement was more significant under low nitrogen. • Intercropping increased both wheat ear density and 1000-grain weight. • Land equivalent ratio of wheat/alfalfa intercrop ranged in 0.79–1.31. • Wheat/alfalfa intercropping had higher yield and land advantage under low nitrogen. • Intercrop of 8-row wheat and 4-row alfalfa with low N was suggested for application. [ABSTRACT FROM AUTHOR]