Resource-conserving technology is a novel crop management approach for intensive rice-based cropping systems in Bangladesh. The study concluded that strip tillage, integrated with effective herbicides and residue mulching, was a profitable alternative to manual weeding in conventional tillage.
Planting crops in exhaustive tilled soil after removing the residues of previous crops is the most common traditional cropping practice in Bangladesh. Generally, rice grown in the soil is usually puddled, followed by manual transplanting. Non-rice crops (mustard, wheat, etc.) are grown in heavily pulverized soils.
These traditional practices pose concerns regarding the sustainability of crop production. Intensive tillage degrades soil structure, depletes soil organic matter (SOM), and increases labor and fuel requirements and overall production costs. It also lags the establishment of succeeding crops, leading to reduced yield.
Further, there is a growing concern regarding labor scarcity for agriculture due to less profit and migration from rural to urban areas within and outside the countries. Thus, there is an urgent need for labor and other input-efficient alternate systems that produce more at fewer costs. Without a new and more sustainable increase in productivity, agricultural supply will hardly keep pace with the rapidly rising demand caused by increasing population and changing consumer preferences with income growth.
Potential strategies to tackle these challenges could be the Resource Conserving Technology (RCT).
The RCT primarily focuses on soil resource savings through minimal tillage, ensuring soil nutrients and moisture conservation through crop residues, and adoption of spatial and temporal crop sequencing. Reduced tillage with residue retention can improve soil physical, chemical, and biological properties, facilitate timely planting, and decrease production costs related to labor, fuel, and machinery. The use of reduced tillage can also reduce drudgery and sustain profit.
However, a meta-analysis of a large set of global data demonstrated RCT may potentially tackle labor and energy shortage in the agriculture of Bangladesh.
In RCT, several minimum soil disturbing options could establish crops. One of them, strip tillage (ST), is one of them which involves 15-25% disturbance of soil surface with a slot up to 6 cm deep and 4-6 cm wide. The farmers are showing interest in growing crops with ST because it reduces cultivation cost, protects soil degradation, and saves water without yield sacrifice.
But ST is criticized due to the inefficient control of weeds. Because the conventional intensive tillage controls the existing weeds by burying them and their seeds into the soil, resulting in the less early emergence of weeds By contrast, for effective weed control in ST, pre-plant non-selective herbicides must be used to kill the existing weeds.
Subsequently, pre-emergence herbicide followed by a post-emergence also needs to apply because of remaining viable weed seeds on the surface still after pre-plant herbicide application.
Nowadays farmers are switching to herbicidal weed control as it is a quick, effective, and low-cost weed control method to address the crisis of labor availability with high wages during peak demand periods. Previous studies confirmed the application of pre-plant, pre-emergence and post-emergence herbicides ensured continuous and effective control of weeds and provided better yield over manual weeding. But, the repeated use of herbicide with the same mode of action may lead to developing quick herbicide resistance in weeds, making weed control more difficult.
Moreover, herbicides’ persistence in the soil and their detrimental effects on succeeding crops is a significant issue. Furthermore, shifts in weed populations due to continuous use of a particular herbicide, less availability of appropriate herbicide molecules with the higher prices, and environmental pollution-related issues urge the need to adopt integrated weed management strategies to increase the sustainability of ST.
Agronomic options like crop residues and crop intensification had reported earlier to manage weeds in ST practice.
There are many pieces of evidence that crop residue retention and crop intensification promote nutrient cycling, increase nutrients availability to crops, and increases SOM content, additionally suppress weeds and increases soil water content, and reduce irrigation water requirements by suppressing soil evaporation. Residue retention could also play an important role in rice-maize-rice systems (R-M-R), where the residues of both crops are generally removed from the fields.
High-yielding R-M-R systems are more extractive of nutrients, particularly N, P, or K than rice-rice systems. Further, the inclusion of mustard in the system and its’ residue retention can improve the nitrogen economy of the following crop.
However, although there are several studies on the effects of ST and residue mulching options on the productivity of different cropping systems, the research work on this practice under R-M-R system is not done on a large scale in Bangladesh. Thus, the current two years of study were conducted with the R-M-R systems with alternative tillage and residue management options to identify Bangladesh’s most productive and profitable options.
Resource conserving technology is a novel crop management approach for intensive rice-based cropping systems in Bangladesh. The study concluded that ST, integrated with effective herbicides and residue mulching, was a profitable alternative to manual weeding in conventional tillage. This approach also saves labor for crop cultivation and sustainable intensification of the summer rice-mustard-winter rice cropping system in Bangladesh under resource-conserving technology practice.
Read the study:
Hossain M, Begum M, Rahman M, Hashem A, Bell R (2021) Resource conservation technology for sustainable productivity of intensive rice-based cropping pattern in Bangladesh. J Agric Sc Food Technol 7(1): 053-060.