Impact of fruit-tree shade intensity on the growth, yield, and quality of intercropped wheat

Interplanting potato with grapes improved yield and soil nutrients by optimizing the interactions of soil microorganisms and metabolites

Interplanting crops is the best method to grow crops synergistically for better utilization of land and agro-resources. Grape (Vitis vinifera) and potato (Solanum tuberosum L.) have highly efficient agricultural planting systems in China, however, how soil physicochemical properties and soil microbial communities and metabolites affect the output of grape-potato interplanting remained unknown. In this study, we employed three planting patterns (CK: grape monocropping; YY: grape interplanted with potato (variety 'Favorita'); LS: grape interplanted with potato (variety 'Longshu7')) at two experimental sites i.e., the Huizhou (2022) site and the Qingyuan site (2023). The grape variety for all planting patterns was 'Sunshine Rose'. Soil samples (top 0-20 cm) at both sites were collected to observe the diversity of bacterial communities and soil metabolites. Our findings revealed that, compared with monocropping, the interplanted systems resulted in higher concentrations of total nitrogen, available phosphorus, and available potassium and enhanced the activities of acid phosphatase, urease, and protease. The potato root exudates also altered the relative abundance of Bacillus, Kaistobacter, and Streptomyces in the rhizosphere. Among the soil metabolites, lipids and organic acids showed the most significant changes. Notably, 13-L-hydroperoxylinoleic acid is the key differentially abundant metabolite involved in the regulation of linoleic acid metabolism pathways. The association analyses of the metabolome, microbiome, and soil physicochemical properties revealed that the interactions of microbes and metabolites resulted in differences in the soil nutrient content, whereas the interactions of 13-L-hydroperoxylinoleic acid and Firmicutes improved the soil nutrient levels and bacterial composition in the interplanting systems. In summary, our findings demonstrated that intercropping grapes with potato 'Favorita' was better with respect to improving soil nutrients, soil enzyme activity, the diversity of soil bacteria, and soil metabolites without causing adverse impacts on grape yield. Overall, this study explained the physiological mechanisms by which soil microorganisms and metabolites promote potato growth in grape interplanting and provided new perspectives for the utilization of soil resources in vineyards.

Multistoried woodlot based agroforestry system for improved resource utilization and incomes for farmer

Diversification of cropping pattern coupled with the development of suitable technology packages is crucial to meet the ever-increasing demand for diversified products and sustained farmers' incomes. We evaluated different woodlot-based multistoried agroforestry systems for their effectiveness to mitigate the devastating effects of climate change by offering multifaceted benefits. Specifically, the present study aimed to assess the yield and probability of woodlot based multistoried agroforestry system with two vegetables, i.e., potato and brinjal during the period of 2019-2020. The vegetables were planted on the floor of the orchard where pineapple were planted in the same row with the trees. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. The results revealed that the upper-storied woody plants and sole vegetables received 100 % Photosynthetically Active Radiation (PAR) but incident light gradually decreased for brinjal and potato, which were grown at the floor of woody trees. The vegetables experienced 55.85(T3), 60.70(T2), 66.38(T1), and 100 (T4) % PAR under different tree crop combinations respectively. In both cases the highest BCR (3.75) and (3.09) was obtained in the ghoraneem + pineapple based multistoried agroforestry system for potato and brinjal production, respectively, which may considered as the best technique for higher production, crop diversification, and maximization of land use efficiency.

Relationship between the baking quality of wheat (Triticum aestivum L.) and the protein composition and structure after shading

Although wheat (Triticum aestivum L.) grain protein content is increased by shade stress, the relationship between the baking quality of wheat flour and protein composition and structure remains unclear. Here, we investigated the effects of shade stress on wheat flour protein composition and structure. The contents of the flour protein, α/β-gliadins and disulfide and hydrogen bonds were significantly increased by shade stress. Glutenins, UPP%, and β-sheet contents also increased, whereas that of α-helices decreased. Spearman correlations revealed that the flour protein content, Glu:Gli ratio, and disulfide, hydrogen, and ionic bonds can predict the specific volume and number of crumb cells in bread, whereas α/β-gliadins content can predict the crumb cell wall thickness and diameter of bread. Under shade stress, variations in protein composition and structure help increase the specific volume and crumb cells number and decrease crumb cell wall thickness and diameter of bread, ultimately leading to improved baking quality.

The Impacts of Planting Patterns Combined with Irrigation Management Practices on Watermelon Growth, Photosynthesis, and Yield

(1) Background: Crop yields in China's arid and semi-arid regions are limited by water shortages. Exploring the interactions and resource utilization among agroforestry species is key to maintaining diversified agricultural production. (2) Objective: An apple-watermelon agroforestry system and watermelon sole-cropping system were compared to quantify how resource availability (light, water) and watermelon performance (leaf photosynthetic rate, growth, and yield) change with irrigation strategies. (3) Methods: A three-year apple and watermelon field experiment was conducted in a young apple orchard in the arid area of central Ningxia to test the effect of light competition and irrigation systems on light environment, leaf photosynthetic rate, plant growth, and yield in watermelon. The experiment encompassed two planting patterns: (i) apple-watermelon agroforestry (AF) and watermelon sole-cropping (SC) and (ii) three irrigation quotas (W1: 105 mm, W2: 210 mm, and W3: 315 mm). (4) Results: The results show that the agroforestry planting pattern extended the growth period of watermelon and increased the leaf area index. Mean daily shade intensity increased by 16.02% from 2020 to 2022. The land equivalent ratio (LER) was >1 in 2021 and 2022. The SWC, leaf photosynthetic rate, LAI, and yield of watermelon in an agroforestry planting pattern were lower than when in a sole-cropping planting pattern. However, under the W1 irrigation strategy, the total soluble solids of the agroforestry planting pattern were 2.27% higher than those of the sole-cropping pattern, and the yield of the agroforestry planting pattern was 2.59% higher than that of the sole-cropping pattern. Under the W3 irrigation strategy, the average watermelon weight in the agroforestry planting pattern was 2.85% higher than that of the sole-cropping pattern. A path analysis showed that the agroforestry planting pattern can increase the yield by increasing soil water content, which is different from the sole-cropping pattern. (5) Conclusions: The results confirm that the apple-watermelon agroforestry planting pattern reduced watermelon yields. However, the LER of the agroforestry system was greater than 1.0. It is reasonable to plant watermelons in young apple forests.

Changes in free amino acid and protein polymerization in wheat caryopsis and endosperm during filling after shading

Over the past several decades, a decreasing trend in solar radiation has been observed during the wheat growing season. The effects of shade stress on grain yield formation have been extensively studied. However, little information on shade stress's effects on protein formation warrants further investigation. Two wheat cultivars were grown under three treatments, no shade as the control group (CK), shading from the joint to the anthesis stage (S1), and shading from the joint to the mature stage (S2), to investigate the effects of shade stress on the free amino acids of the caryopsis and endosperm and protein accumulation during grain filling. The dry mass of caryopsis and endosperm was significantly decreased under shade stress, whereas Glu, Ser, Ala, and Asp and protein relative content increased during grain filling. The observed increases in total protein in S1 and S2 were attributed to the increases in the SDS-isoluble and SDS-soluble protein extracts, respectively. S1 improved polymer protein formation, but S2 delayed the conversion of albumins and globulins into monomeric and polymeric proteins. Moreover, shade stress increased the proportion of SDS-unextractable polymeric protein, which represented an increase in the degree of protein polymerization. The polymerization of protein interrelations between protein components and accumulation in caryopsis and endosperm provided novel insights into wheat quality formation under shade stress.

Yield and related traits of three legume crops grown in olive-based agroforestry under an intense drought in the South Mediterranean

Heat and drought stresses have become more frequent and intense in the Mediterranean, strongly influencing arable crop phenology, growth, and grain yield. Agroforestry systems can effectively buffer the adverse climate conditions and stabilize or even increase crop yield under climate change. However, the positive effects of agroforestry remain uncertain due to the possible intense competition between trees and crops, especially for legume crops that have been less studied than cereals in such context. This study aimed to assess the response of the phenology, growth, grain yield, and yield-related traits of chickpea (Cicer arietinum), faba bean (Vicia faba), and lentil (Lens culinaris) to olive-based agroforestry (AFS) as compared to sole crops system (SCS) in the South of the Mediterranean. We conducted a field experiment during two growing seasons marked by an intense drought, either at the beginning (year 1) or at the end (year 2) of the crop cycle. Crop growth and yield were lower in year 1 than in year 2, reflecting the adverse growing conditions caused by the early drought. They were also lower in AFS than in SCS for both years, indicating that trees had competitive effects on crops. In year 1, the yield loss of grains in AFS was 66 % for lentil, 47 % for chickpea, and 43 % for faba bean compared to SCS, confirming the greater shade sensitivity of lentil. In year 2, the reduction was significantly smaller and was about 46 %, 34 %, 38 % for lentil, chickpea and, faba bean, respectively. The number of pods and grains were the most affected yield components by agroforestry and drought timing across the three legumes crops. Similar responses were found when comparing crops at different distances to trees within the AFS field. Crops generally had lower biomass and yield, explained by fewer pods and grains, on the northern side of trees compared to the southern side of trees or the middle of tree inter-rows, causing significant spatial heterogeneity in crops. However, lentil and chickpea had a positive response to shade during the early drought year while a negative response during the late drought year, suggesting that the benefits of the microclimate created by olive trees express depending on drought timing and crop physiology. Our study supports legume integration into AFS, suggesting that chickpea should be considered during high-stress conditions, while faba bean should be preferred during low-stress conditions.

Olive agroforestry shapes rhizosphere microbiome networks associated with annual crops and impacts the biomass production under low-rainfed conditions

Agroforestry (AF) is a promising land-use system to mitigate water deficiency, particularly in semi-arid areas. However, the belowground microbes associated with crops below trees remain seldom addressed. This study aimed at elucidating the effects of olive AF system intercropped with durum wheat (Dw), barely (Ba), chickpea (Cp), or faba bean (Fb) on crops biomass and their soil-rhizosphere microbial networks as compared to conventional full sun cropping (SC) under rainfed conditions. To test the hypothesis, we compared the prokaryotic and the fungal communities inhabiting the rhizosphere of two cereals and legumes grown either in AF or SC. We determined the most suitable annual crop species in AF under low-rainfed conditions. Moreover, to deepen our understanding of the rhizosphere network dynamics of annual crops under AF and SC systems, we characterized the microbial hubs that are most likely responsible for modifying the microbial community structure and the variability of crop biomass of each species. Herein, we found that cereals produced significantly more above-ground biomass than legumes following in descending order: Ba > Dw > Cp > Fb, suggesting that crop species play a significant role in improving soil water use and that cereals are well-suited to rainfed conditions within both types of agrosystems. The type of agrosystem shapes crop microbiomes with the only marginal influence of host selection. However, more relevant was to unveil those crops recruits specific bacterial and fungal taxa from the olive-belowground communities. Of the selected soil physicochemical properties, organic matter was the principal driver in shaping the soil microbial structure in the AF system. The co-occurrence network analyses indicated that the AF system generates higher ecological stability than the SC system under stressful climate conditions. Furthermore, legumes' rhizosphere microbiome possessed a higher resilient capacity than cereals. We also identified different fungal keystones involved in litter decomposition and drought tolerance within AF systems facing the water-scarce condition and promoting crop production within the SC system. Overall, we showed that AF reduces cereal and legume rhizosphere microbial diversity, enhances network complexity, and leads to more stable beneficial microbial communities, especially in severe drought, thus providing more accurate predictions to preserve soil diversity under unfavorable environmental conditions.