The experiment was carried out from July to October 2021 in Baleendah District, Bandung Regency, West Java Province, Indonesia. The location of the land is located at an altitude of about 660 meters above sea level with inceptisol soil types. Laboratory analysis was carried out at the Laboratory of Soil Fertility and Plant Nutrition, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, Sumedang Regency.
The materials used in this experiment were compost, corn seed, and herbicide with the active ingredient atrazine. Fertilization is done using straw compost which is left for about 1 year, urea (45% N), TSP fertilizer (46% P2O5), and KCl (50% K2O). The tools used in this research are analytical balance, oven, knapsack, knife, scissors, plastic bag, ruler/meter, sickle, hoe, bucket, and laboratory tools to measure microorganism activity.
The field experiment used a two-factor experiment with a split-plot design in a randomized block design. The main plot factor is organic matter, consisting of three levels, namely:
b1 : Low C-organic content (1.02%)
b2 : Medium C-organic content (2.50%)
b3 : High C-organic content (3.50 %)
The subplot factor was the dose of the herbicide Atrazine, consisting of five levels:
d0 : No herbicide
d1 : Atrazine dose 1.0 kg a.i./ha
d2 : Atrazine dose 1.4 kg a.i./ha
d3 : Atrazine dose 1.8 kg a.i./ha
d4 : Atrazine dose 2.2 kg a.i./ha
d5 : Atrazine dose 2.6 kg a.i./ha
The data from the analysis of variance was further tested with the Scott-Knott test at a 5% significance level.
1. Total weed dry weight
Total dry weight of weeds was the total dry weight of weeds in each treatment plot and each replication. Weed dry weight was observed on weeds taken from sample plots at 2, 4, and 6 weeks after application. The weeds were cut above the soil surface, then dried in a drying oven at a temperature of 800C until they reached a constant weight and then weighed. Weed dry weight observed per species, other weeds, and total weeds.
2. Sweet Corn Crop Yield
Observation of sweet corn weight per experimental plot was carried out at harvest time.
3. Observation of Microorganism Activity in Soil
Observations of microorganism activity were carried out at the Laboratory of Soil Fertility and Plant Nutrition, Faculty of Agriculture, Universitas Padjadjaran, Jatinangor, Sumedang Regency. Observations in the soil were indicated by the respiration of microorganisms in the soil, observed at 30, 60, and 90 days after application.
4. Herbicide Persistence in Soil
Observation of the persistence of atrazine herbicide was carried out by bioassay with an indicator plant, namely cucumber, in the Greenhouse of the Faculty of Agriculture, Universitas Padjadjaran. Observations were made on herbicide persistence in the soil at 30, 60, and 90 days after application.