The Residual Effect of Pre-Rice Green Manuring on a Succeeding Wheat Crop (Triticum aestivum L.) in the Rice-Wheat Cropping System in Banke, Nepal

Rice-wheat is the most widely used cropping pattern in Nepal. This cereal-based cropping system is highly nutrient exhaustive and unsustainable from a soil management perspective. They contribute neither nitrogen nor biomass to the soil. The net effect is the export of nutrients from the soil. The unused period between wheat harvest and rice transplanting is the summer fallow, and the incorporation of green manure during this short period increases the yield of both crops and improves the soils chemical properties. Altogether, there were 9 treatments and 3 replications with the randomized complete block design (RCBD). Dhaincha, sun hemp, black gram, cowpea, mung bean, and rice bean were used as pre-rice green manure. No chemical fertilizers were used for the green manure, and in wheat, 150 : 50 : 50 NPK kg/ha was applied. Goat manure was applied at the rate of 10 t/ha. The main objective of the study is to ascertain the residual effect of pre-rice green manuring on the chemical properties of the soil and the yield attributes of the succeeding wheat crops. The chemical properties of the soil were analyzed before and after the harvesting of wheat, and the yield attributes parameters were analyzed. The result showed that the green manure-treated plots gave a significantly higher yield as compared to solely chemical fertilizers-treated plots. The maximum grain yield was obtained from black gram (5.870 t/ha). There was a 39.76% increase in the grain yield in the black gram-incorporated plots as compared to the only-chemical fertilizers-treated plots. There was a highly (<0.001) significant difference in the soil organic matter of the green manure-treated plots and the only-chemical fertilizers-treated plots. The sun hemp-incorporated plot increased the soil organic matter by 71% when compared to the only-chemical fertilizers-treated plot. There was no significant residual effect of pre-rice green manuring on the soil pH in a one-cropping season. However, there was a significantly higher residual effect of the green manure on the soil’s total nitrogen content in all green manure-treated plots. It was found to be the highest (0.087%) in pre-rice dhaincha. The overall results indicate that the incorporation of pre-rice green manuring improved the soil’s chemical properties and increased the grain yield of the succeeding wheat crops in a rice-wheat cropping system.

Beetroot and radish production under different doses of green manures

Green manuring with spontaneous species from Caatinga biome has become an important strategy in production vegetables. One of the great challenges in tuberous vegetables production is to define an optimized quantity that provides a high productive yield with economic efficiency of production system. The objective of this study was to optimize agronomically and economically the production and its components of tuberous crops of beetroot and radish when manured with different amounts of green manures biomass, Merremia aegyptia and Calotropis procera from Caatinga biome, in two cropping seasons. The experimental design was a randomized complete block with five treatments and five replications. Treatments consisted of green manures amounts (16, 26, 36, 46, 56 t ha-1). The maximum agronomic efficiency of beetroot and radish was obtained with incorporation of 49.87 and 39.43 t ha-1 of M. aegyptia and C. procera, respectively, and the production maximum economic efficiency was reached when 36.14 and 36.48 t ha-1, respectively, of biomass of these green manures were added to the soil. The returns rate obtained in beetroot and radish cultivation using the manures optimized amounts were 1.42 and 1.32 reais obtained for each real invested in the production of these tuberous.

Beet-arugula intercropping under green manuring and planting density induce to agro-economic advantages

ABSTRACT One of the biggest challenges in the intercropping system of two crops is to obtain the optimal dose of green manure and the adequate population density of the crops. So, the objective of this work was to evaluate the performance of beet and arugula intercropping, influenced by green manuring with Merremia aegyptia and Calotropis procera and arugula population densities in two cultivation years, in semi-arid environment. The experimental design used was in randomized complete blocks, with the treatments arranged in a 4 x 4 factorial scheme, with 4 repetitions. The first factor of this scheme consisted of equitable amounts of M. aegyptia and C. procera biomass (20, 35, 50 and 65 t ha-1 on a dry basis) and the second factor, by arugula population densities (40, 60, 80 and 100% of the recommended density for single cropping, corresponding to 400, 600, 800 and 1,000 thousand arugula plants ha-1). The production and its components were evaluated on beet and arugula. In addition to these characteristics, the following agro-economic indicators were also determined for each treatment: system productivity index (SPI), land equivalent coefficient (LEC) and monetary equivalent ratio (MER). The greatest agro-economic advantages of the beet with arugula intercropping were achieved with a system productivity index (SPI) of 53.47 t ha-1, land equivalent coefficient (LEC) of 0.84 and a monetary equivalent ratio (MER) of 1.56, respectively, combining 65 t ha-1 of M. aegyptia and C. procera biomass with the arugula population density of 1,000 thousand plants ha-1. The maximum optimized commercial productivity of beetroots in the system intercropped with arugula was 23.20 t ha-1 using 65 t ha-1 of M. aegyptia and C. procera and in the arugula population density of 1,000 thousand plants ha-1, while the maximum arugula productivity intercropped with beet was 9.65 t ha-1, in the same combination of green manures amount and arugula population density.

Long Term Resource Conservation Technologies Sustained Yield, Microbial Activities and Soil Physico-chemical Properties in Rice-green Gram Cropping System

PurposeMicrobial communities in rhizospheric soil play a significant role in sustaining the soil quality and also recognized as key ecological indicators to assess the soil health. MethodsWe studied the long-term effects of resource conservation technologies on functional microbial diversity and their interactions with soil biochemical properties and enzymatic activities in tropical rice-green gram cropping system. The experiment included conventional practice (CC), brown manuring (BM), green manuring (GM), wet direct drum sowing (WDS), zero tillage (ZT), green manuring-customized leaf colour chart based-N application (GM-CLCC N) and biochar (BC) treatments. ResultsThe result revealed that microbial biomass nitrogen (N), carbon (C) and phosphorus (P) in GM practice increased by 23.3, 37.7 and 35.1%, respectively over CC. The Shannon index and McIntosh index were higher by 86.9% and 29.2% in GM as compared to conventional practice and significantly correlated with microbial biomass (C & P) and soil microbial populations whereas, Shannon index was positively correlated with the microbial biomass (C, N & P) and soil enzyme activities. Principal component analysis showed a significant separate cluster among the treatments amended with and without biomass addition. ConclusionsMoreover, dominance of carbon utilizing microbes in biomass amended treatments indicated that these could supply good amount of labile carbon sources on real time basis for microbial activity. Which may protect the stable carbon fraction in soil, hence could support higher build-up of carbon in long run and could offer sustainable yield under rice-green gram soil.

Effects of Organic Manures and Green Manuring on Growth, Yield, Economics and Quality of Lemongrass (Cymbopogon Flexuosus L.) In Custard Apple (Annona Squamosa L.) Based Agri-Horti System

A field experiment was conducted to explore the effects of organic manures and green manuring practices on growth, yield attributes, quality and economics of lemongrass (Cymbopogon flexuosus L.) under custard apple (Annona squamosa L.) based agri-horti system. The findings indicated that growth, yield attributes and yield as well as oil composition, soil nutrient status, microbial populations were significantly increased due to the use of both organic manures and green manuring. The significantly higher results were obtained with vermicompost (2.5 t/ha) + Azotobacter, which was found superior over other practices in terms of growth, yield attributes, oil composition and its quality and soil nutrient status as well as economics of crop cultivation. Bangladesh J. Bot. 50(3): 499-506, 2021 (September)

Green manuring with crimson clover as an alternative to mineral fertilization in maize production

Role of mineral fertilizers is to complement the soils’ indigenous supply of minerals for crop plants nutrition. Among the mineral nutrients, nitrogen is generally considered as the most yield-contributing. Obtaining nitrogen from legumes is potentially more sustainable than from industrial sources. Crimson clover (Trifolium incarnatum L.) has long been appreciated as cover crop grown for green manuring due to its capability for binding the atmospheric nitrogen into plant-available form. Green manuring effects of crimson clover for succeeding maize crop were tested in 2019 year on two locations of Northeastern Croatia differing in soil texture: 1) on the site A where the soil was compact and dominated by clay and 2) on the site B where the soil was loose and dominated by loam. The research was conducted in a year with favourable rainfall during maize vegetation. Results have shown that green manuring with crimson clover for maize as the main crop delivered somewhat lower maize grain and aboveground mass yields than the conventional full-dose mineral fertilization on deep fertile soils around Osijek (Northeastern Croatia). When compared to conventional agronomy, green manuring was associated with additional agrotechnical operations required for crimson clover cover crop establishment and its herbage incorporation into soil prior to seeding main maize crop. Research should be continued in more different environments (year × location combinations) in order to produce reliable evaluation of crimson clover’s green manuring services.

Effects of Different Organic Soil Amendments on Nitrogen Nutrition and Yield of Organic Greenhouse Tomato Crop

Manure is a common source of nitrogen (N) in organic farming. However, manure is not always easily available, while the maximum N amount added as animal manure in organic agriculture is restricted by EU regulations. The present study was designed to test whether green manuring with a warm-season legume and intercropping with a cold-season legume can substitute farm-yard manure or compost as N sources in organic greenhouse tomato crops. To test this hypothesis, a winter-spring (WS) tomato crop was installed in February following the incorporation of crop residues of an autumn-winter (AW) tomato crop intercropped with faba bean, which had been fertilized with cowpea residues as green manure. This treatment, henceforth termed legume treatment (LT), was compared with the use of compost or manure as an N fertilization source in both tomato crops. In addition, a combination of compost and LT was also used as a fourth treatment. The results showed that green manuring with legumes and particularly cowpea can contribute a significant amount of N to the following organic tomato crop, through the biological fixation process. Nevertheless, legumes as green manure, or compost, or their combination cannot efficiently replace farmyard manure as an N fertilization source. Compost exhibited a slow mineralization course.