Secondary metabolites from weeds have potential as a natural herbicide and are safe for the main crop. This study aimed to screening secondary metabolites in Mikania micrantha extract and their effect on the agronomic, physiological and histological characteristics of barnyardgrass and lowland rice. A non-factorial randomized block design was used, with extract concentrations of Mikania micrantha (0; 20; 40; 60; 80; 100 %) and 2,4-D dimethyl amine herbicide as comparison. The M. micrantha extract presented favonoids, tannins, alkaloids and saponins. The concentration of 20-100 % inhibited the barnyardgrass growth, but was considered safe for the lowland rice, and increased the root length and volume, while the concentration of 60 % increased the number of leaves and stomatal density in the lowland rice. The concentration of 20-100 % significantly inhibited the root volume, biomass, SPAD total chlorophyll and growth reduction of barnyardgrass, and it was classifed as an inhibitor. The barnyardgrass tocixity also increased as the concentration grew from 60 to 100 %. The M. micrantha extract reduced the barnyardgrass growth by 63.5 %, being close to the percentage presented by the 2,4-D dimethyl amine (65.6 %).

The research was carried out to study the distribution of some macro nutrients and chemical Properties in some semi–arid soils of Borno state. Three composite soil samples were collected at different locations at depth of 0-20 cm which were analysed for some macro nutrients and chemical properties. University of Maiduguri (Unimaid) soil is slightly acidic to neutral in reaction,  low in electrical conductivity (EC), high base saturation, low in percent organic carbon, moderate in calcium, high in magnesium, low in potassium, high in sodium, low in available phosphorus. Dalori soils were neutral in reaction, low in EC, high base saturation low in percent organic carbon, low in calcium, high in magnesium, low in potassium, high in sodium, low in available phosphorus. Gongulong soil was moderately acidic in reaction, moderate in EC, high base saturation, moderate in percent organic carbon, high in calcium, very high in magnesium, moderate in potassium, high in sodium, low in available phosphorus.

This study aimed to identify the optimum rice stem cutting size combined with the application of Seprint liquid organic fertilizer (SLOF) to promote the growth and yield of ratoon rice. This research was conducted in a greenhouse at the Faculty of Agriculture, University of Muhammadiyah Sumatera Utara, North Sumatra Province, Indonesia, from January to August 2018. The experiment was set up as a completely randomized design factorial with four replications. The first factor consisted of the cutting sizes of the rice stem (R1 = 5 cm, R2 = 10 cm, and R3 = 15 cm) and the second factor involved the SLOF dosage (S1 = 5 mL L −1 , S2 = 10 mL L −1 , and S3 = 15 mL L −1 ). The parameters were analyzed using analysis of variance (ANOVA), and the means were determined by Duncan’s multiple range test (DMRT). The results showed that the R2 treatment significantly increased the ratoon rice height at 10 to 30 days after cutting (DAC), the number of tillers at 40 to 60 DAC, the number of productive tillers, and the yield per hectare. The S2 and S3 applications at significantly increased the yield per hill and ratoon rice height at 20 DAC. The R2S1 and R2S2 combination treatments significantly increased the number of filled grains per panicle and the ratoon rice height at 10 DAC. Cutting the stems at 10 cm combined with various dosages of SLOF resulted in greater growth and yield of ratoon rice for achieving an adequate food supply.

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