Research Article
Evaluation of maize-based intercropping on runoff, soil loss, and yield in foothills of the Indian sub-Himalayas
- Rajeev Ranjan, N.K. Sharma, Ambrish Kumar, Monalisha Pramanik, Harsh Mehta, P.R Ojasvi, R.S. Yadav
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- Published online by Cambridge University Press:
- 17 May 2021, pp. 69-84
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Soil and nutrients losses due to soil erosion are detrimental to crop production, especially in the hilly terrains. An experiment was carried out in three consecutive cropping seasons (2012–2015) with four treatments: sole maize; sole maize with plastic mulch; maize and cowpea under plastic mulching; and maize and soybean under plastic mulching in randomized block design (RBD) to assess their impact on productivity, profitability, and resource (rainwater, soil, and NPK nutrients) conservation in the Indian sub-Himalayan region. The plot size was 9 × 8.1 m with 2% slope, and runoff and soil loss were measured using a multi-slot devisor. The results showed that mean runoff decreased from 356 mm in sole maize with plastic mulch plots to 229 mm in maize + cowpea intercropping with plastic mulch, representing a reduction of 36% and corresponding soil loss reduction was 41% (from 9.4 to 5.5 t ha−1). The eroded soil exported a considerable amount of nitrogen (N) (13.2–31.4 kg ha−1), phosphorous (P) (0.5–1.7 kg ha−1), and potassium (K) (9.9–15.6 kg ha−1) and was consistently lower in maize + cowpea intercropping. The maize equivalent yield (MEY) was significantly higher in maize + cowpea with plastic mulch intercropping than the other treatments. These results justify the need to adopt maize with alternate legume intercrops and plastic mulch. This strategy must be done in a way guaranteeing high yield stability to the smallholder farmers of the Indian sub-Himalayan region.
Silicon dioxide nanofertilizers improve photosynthetic capacity of two Criollo cocoa clones (Theobroma cacao L.)
- Pedro Gómez-Vera, Héctor Blanco-Flores, Ana Marta Francisco, Jimmy Castillo, Wilmer Tezara
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- Published online by Cambridge University Press:
- 17 May 2021, pp. 85-102
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Studies on the effect of nanofertilizers (NF) in physiological performance of plants is scarce, especially that related to substances encapsulated into silicon dioxide (SiO2) nanoparticles in cocoa plants. The effect of foliar application of SiO2-NF on nutrient contents, gas exchange, photochemical activity, photosynthetic pigments, total soluble protein (TSP), photosynthetic nitrogen use efficiency (PNUE), and growth in seedlings of two cocoa clones (OC-61 and BR-05) in a greenhouse was assessed. Spraying with SiO2-NF increased net photosynthetic rate (A) by 16 and 60% and electron transport rate (J) by 52 and 162% in clones OC-61 and BR-05, respectively, without changes in photosynthetic pigment concentration in either clone. The SiO2-NF caused a decrease of 37 and 22% in stomatal conductance in OC-61 and BR-05, respectively; a similar trend was observed in transpiration rate, causing an increase of 42 and 100% in water use efficiency in OC-61 and BR-05, respectively. In both clones, diameter of graft increased on average 28% with SiO2-NF. Higher photosynthetic capacity was related to an increase in leaf N, P, and TSP. A significant reduction in PNUE (A/N ratio) was found in OC-61, whereas in BR-05 PNUE increased after spraying with SiO2-NF. Overall, spraying with SiO2-NF had a positive effect on photosynthetic processes in both cocoa clones, associated with an increase in nutrients content, which translated into improved growth. A differential physiological response to spraying with SiO2-NF between clones was also found, with BR-05 being the clone with a better physiological response during the establishment and development stages.
Strategies to mitigate economic hardship among family dairy farms of Central Mexico
- Carlos Galdino Martínez-García, Claire Clugston, Carlos Manuel Arriaga-Jordán, Jesús Olmos-Colmenero, Michel André Wattiaux
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- Published online by Cambridge University Press:
- 11 May 2021, pp. 103-112
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The economic hardship of dairy producers has worsened in the last decade because of increasing costs of production. A field survey with 51 dairy farmers was conducted to explore strategies to mitigate economic hardship. Factor and cluster analyses were conducted to characterize the farmers and their farms. Differences among groups regarding changes adopted to increase incomes, to reduce costs, and to pay bills were tested using Fisher’s exact test. Four factors explained 76.2% of the cumulative variance and four groups were identified: “stagnant farms” were in group 1, with the lowest daily income over concentrate feed cost (DIOCFC) and the least number of changes, “effectively management farms” were in group 2, with the highest DIOCFC and the highest number of income-increasing changes, the “cost reducing farms” were in group 3, with the smallest in size with a focus on cutting cost, and the “mixed strategy farms” were in group 4, with the largest herd size. Most prevalent income-increasing strategies included attempts to improve cow nutritional balance and milk composition, whereas the most prevalent cost-reducing strategies included reductions in input purchases of inputs (concentrates and fertilizers) and selected household expenses. Selling cows was a common strategy to generate cash in acute hardship situations. In conclusion, responses to economic hardship varied substantially among groups of farms, cost-reducing strategies were linked to lower cow productivity and lower technological levels, but income-increasing strategies were linked to higher cow productivity and higher DIOCFC. Our findings may contribute to the design of extension initiatives to promote useful strategies to help mitigate economic hardship on dairy farms.
Changes in soil carbon, nitrogen, and phosphorus contents, storages, and stoichiometry during land degradation in jasmine croplands in subtropical China
- Qiang Jin, Josep Peñuelas, Jordi Sardans, Estela Romero, Sicong Chen, Xuyang Liu, Shaoying Lin, Weiqi Wang
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- Published online by Cambridge University Press:
- 17 May 2021, pp. 113-125
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Soil degradation is characterized by loss of soil organic matter, decline in fertility, imbalance in elemental content, deterioration of soil structure, and overall a deterioration of soil environment. According to the classification method of Pieri et al. (1992), the soil is classified into different degradation classes by calculating the soil structural stability index (St) of each sample point. We aimed to investigate changes in the contents, storages and stoichiometry of soil carbon (C), nitrogen (N), and phosphorus (P) together with changes in soil physical traits along a soil degradation gradient in jasmine croplands in Fuzhou area (China). The content and storage of soil C and N decreased with increasing intensity of land degradation. Soil organic C content was 15.4%, 32.3%, and 38.8% lower, respectively, in the low, medium, and high degree of degradation soils, than in the nondegraded soils. The soil C:N ratio was 18.5% higher in soils in the middle degree of degradation than in the nondegraded soils. Compared with nondegraded soils, the bulk density of the degraded soils increased and water content decreased. The decrease of soil pH coupled with salinity (conductivity) and the loss of aggregate stability are the main traits that distinguish degraded from nondegraded soils. We also detected a general N and P deficiency that is aggravated by the degradation process. Unreasonable management easily leads to degradation associated with a loss of organic C and total soil nutrients, thus impairing even more a general N and P deficiency in this area. Therefore, higher inputs of organic fertilizer should be added to alleviate the lack of organic matter, and appropriate burial should be conducted to reduce nutrient loss. Moreover, a rise of N and P fertilizer application is also advisable.
Performance of elite genotypes of barley, chickpea, lentil, and wheat under conservation agriculture in Mediterranean rainfed conditions
- Mina Devkota, S. B. Patil, Shiv Kumar, Zakaria Kehel, Jacques Wery
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- Published online by Cambridge University Press:
- 14 June 2021, pp. 126-143
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Conservation agriculture (CA) practices are becoming more important in Mediterranean rainfed areas due to their potential to minimize climatic risk, reduce soil erosion, and improve soil quality and water availability. Due to minimum soil disturbance and crop residue retention, the soil environment for crop growth and development can differ between CA and conventional tillage (CT) practice. However, breeding targets for improving yield performance in CA system remain poorly explored. The objective of this study was to assess the performance of elite genotypes of barley, chickpea, lentil, and wheat grown under CA, a promising alternative agricultural practice in the Mediterranean rainfed conditions. A three-year field study, with contrasting rainfall pattern, was conducted in the International Center for Agriculture Research in the Dry Areas’s research field in Morocco to evaluate the tillage × genotype interaction and its consequence for yield performance of barley, chickpea, lentil, and wheat. Thirteen elite genotypes for each crop were planted under both CA and CT systems. Wheat and chickpea produced significantly higher grain yield (+62% for wheat and +43% for chickpea) under CA than in CT, while lentil and barley performed equally under both systems. Significant effect of tillage × genotype was more frequent for chickpea and wheat than for barley and lentil. Increased yield under CA, mainly in dry year, was associated with higher harvest index (HI). For each crop species yield was mainly influenced by rainfall amount and distribution (75–88% yield variation), and tillage × genotype was of little importance. The overall results suggest that a specific breeding program for CA in lentil, chickpea, wheat, and barley may not be efficient. Few tillage × genotype interaction, especially in dry years, indicated that breeding target on increasing HI, tolerance to drought (high yield in dry years), and potential yield (high yield in wet year) can help to improve yield performance of chickpea, lentil, and wheat genotypes in CA system. Varieties with wider adaptability considering drought tolerance, higher yield with stability, and adoption of CA practices are important in the context of the Mediterranean rainfed environment. Integrating trade-off analysis between yield potential and stability in a rainfall gradient in both CT and CA in the national certification scheme of varieties may be more efficient than developing breeding programs for each type of tillage system.